Course Introduction This course is a continuation of Body Systems and Medical Terminology 1. You'll continue to learn about various body systems, drug delivery systems, drug administration routes, drug classifications, and commonly used medications for various organ system disorders. You'll also learn basic medication calculations, storage, how to assist patients with administration, and proper documentation.   Course Materials All of your course materials are included in this course experience. You'll find it easiest to study this course by following these steps: Look over the syllabus, paying close attention to the course and lesson objectives. Read each objective. Pay close attention to main concepts and definitions. Complete each assignment as you come to it. When you've completed each section, look over the lesson review. When you're confident you understand the material, complete the lesson review.   Course Objectives By the end of this course, you'll be able to Identify the anatomy, physiology, and diseases and treatments of the integumentary and musculoskeletal systems Identify the anatomy, physiology, and diseases and treatments of the sensory and nervous systems Identify the anatomy, physiology, and diseases and treatments of the immune system Explain how the Six Rights of Drug Administration dictate proper drug administration and storage  

Lesson 1 Overview In this lesson, you’ll learn the basic principles of the integumentary and musculoskeletal systems. The integumentary system is comprised of skin, hair, nails, and various glands. The main function of the integumentary system is to protect your internal organs as well as regulate various secretions and senses. The musculoskeletal system is comprised of bones, joints, and muscles and is mainly responsible for protection, support, and body movements. You’ll also gain knowledge of various diseases of the integumentary and musculoskeletal systems along with available treatment options. While discussing the treatment of these disorders, you’ll learn about the medications used to treat each disorder. Medications listed throughout this lesson are listed as generic names with brand names provided in parenthesis.   Lesson Objectives Describe the anatomy and physiology of the integumentary system Explain integumentary system disorders and common treatment options Explain various components and functions of the musculoskeletal system Describe diseases and treatments of the musculoskeletal system  

Introduction The integumentary system is the body system that provides protective coverage for your internal organs. This integumentary system comprises the skin, hair, nails, sweat glands, and sebaceous (oil) glands. Nails protect the ends of fingers and toes. The skin, hair, sebaceous glands, and sweat glands enable the body to regulate temperature.   Skin Although the skin may appear to be an inactive sheet of tissue, it's a dynamic organ with blood vessels and nerves just like any other organ. The skin is a vital organ that interacts with several other organ systems and has several functions.  Some of the skin's functions are as follows: The skin provides protection from the outer environment. The skin acts as a barrier against foreign pathogens. The skin sends the pain, temperature, pressure, and touch stimuli to the brain. When skin is exposed to the sun, it helps in synthesizing vitamin D, an essential vitamin needed to carry out various body functions. The skin weighs somewhere between seven and nine pounds and takes up, on average, 20 square feet. There are about 300 million skin cells. Each square centimeter of your skin contains about four meters of small branches of the peripheral nerves. This intricate system of nerves allows you to sense very subtle changes in the immediate environment.   Your skin senses touch, pressure, temperature, and pain with different types of nerve fibers. These then send a signal to the brain; the brain decodes the signal and sends a response to the affected body part.   A single centimeter of skin contains meter-long blood vessels. In addition to supplying blood and essential nutrients to the skin, blood vessels allow the skin to help regulate body temperature. Think of the last time you exercised. Whenever you exercise, your heart rate increases to deliver more oxygen to your working muscles. The metabolism of your muscles generates heat. To maintain a stable body temperature, your body must get rid of this extra heat. This occurs mainly through sweating. Evaporation of sweat from your skin carries away heat. The tiny blood vessels in your skin dilate to lose heat, making your skin warm and flushed. In the opposite situation, when you're exposed to extremely cold temperatures, the blood vessels in your skin become more constricted. This shunts blood flow, along with heat, away from skin and inward to protect vital organs. Shivering also is an attempt of your body to produce heat to counteract extremely cold temperatures. *Your skin is an organ that can grow on its own. Skin grafting is commonly used to grow and repair blood vessels, trauma wounds, deep injuries, and burns. Grafting is a process of taking a piece of your own skin or a piece of donor skin and transplanting it to the affected site to grow and repair.   Sweat and Sebaceous Glands Sweat glands are located deep in the dermal layer, very close to the subcutaneous layer of the skin. There are two types of sweat glands: eccrine and apocrine. There are both sweat glands and modified sweat glands. Eccrine sweat glands are numerous, important, and widespread throughout your body. These tiny coiled tubes reach the epidermis through crooked ducts called pores. Eccrine sweat glands produce a watery sweat. Apocrine sweat glands are found primarily in the axillae (armpits) and in the pigmented skin areas around the genitals. The apocrine sweat glands produce a thicker, milky secretion that can be odorous. The milk-producing mammary gland is actually a modified sweat gland, but it doesn't work full time like the sweat gland. The mammary gland secretes milk only after the birth of a child. Other modified sweat glands are the ceruminous glands, located in the skin that lines the external auditory canals (your ears). Instead of sweat, these glands secrete earwax, or cerumen.  Flask-shaped sebaceous glands are also located in the dermis. Commonly attached to hair follicles, the sebaceous glands secrete an oily substance called sebum, which is released through ducts into the hair follicles. Sebum oils the hair, lubricates the skin, and prevents water loss. *Approximately two million sweat glands work together to help your body maintain its proper temperature. As muscle movement and physical activity generate body heat, the sweat glands secrete water, more commonly known as perspiration. As the perspiration evaporates, the body becomes cooler. On average, a person sweats approximately one quart of water each day. That's why it's important to drink enough water to replenish body fluids.   Hair and Nails Hair and nails are modified forms of the epidermis. In both, the horny cells, filled with keratin, are pushed through the epidermis. Because hair and nails are composed of dead cells, no pain is felt when they're cut. Hair and nails provide protection. Hair keeps heads warm and serves as a filter system for ears, eyes, and nose. Each strand of hair on your body is a complex entity with a full support system. Some parts of the human body have no hair, such as the palms of the hands and the soles of the feet. But other parts have an abundance of hair. Your hair is constantly shed and replaced as more horny cells move upward from hair follicles through the hair shaft. Nails protect the ends of fingers and toes. Nails provide physical support to the fingertips to allow you to pick up small objects. Hair Hair fibers are composed of a tightly fused meshwork of horny cells. A single hair is composed of four basic parts—the hair shaft, hair root, hair follicle, and the papilla. The hair shaft is the visible part of the hair. The hair root is embedded in the dermis. If you pluck a hair from the root, you'll see the hair follicle, a bulblike attachment at the end of the hair. The follicle consists of the root and its coverings. The papilla is a loop of capillaries enclosed within connective tissue. Nails Nails are hard, keratin-filled plates that are composed of tightly cemented, horny cells. A nail grows from the lunula, the white crescent at the base of the nail. Fingernails grow indefinitely at the rate of about one millimeter a week unless they're cut or broken. Toenails also grow indefinitely, but at a slower rate than fingernails. The cuticle is the narrow band of the epidermis that extends from the nail wall onto the surface. The pinkish color seen beneath the nail is produced by underlying capillaries.    Key Points The three layers of your skin are called the epidermis, dermis, and hypodermis. The epidermis provides protection and physical barrier to foreign pathogens. The dermis contains sweat glands, sebaceous glands, and hair follicles and provides protection against disease-causing pathogens and releases histamine to protect the skin against allergens. The hypodermis produces and stores fat and connects the skin to the body organs to give shape to your body. Sebaceous glands produce oil that keeps hair and skin lubricated as well as prevent water loss. Sweat glands produce sweat to maintain body temperature.              

Introduction Skin tissue is mainly affected by aging. Aging affects every organ system in the body, but skin changes are the most obvious. As you grow older, the skin loses its elasticity and becomes rough and dry, resulting in wrinkles. Skin can be damaged by sun exposure for long time periods. There are many cosmetic products available to help protect the skin. It's important to apply an appropriate amount of sunscreen frequently if your skin is exposed to the sun. Common disorders of the skin include infections, lesions, pressure ulcers, inflammatory diseases, burns, and acne. Infections can be caused by bacteria, viruses, fungi, and parasites. Allergic reactions can affect the skin and include symptoms such as inflammation, itching, and hives. Injuries and wounds can also traumatize the skin.    Skin Infection Skin infections can be caused by various microorganisms, including bacteria, fungi, viruses, and parasites. An infection can be local, with symptoms of inflammation, pus, blisters, and pain. If untreated, an infection can spread to internal organs and cause systemic infection if it reaches the bloodstream. Signs and symptoms of severe infections include fever, dehydration, and increased white blood cells (WBCs) in the blood. Severe infection might require intravenous antibiotics and prolonged hospitalization. Bacterial infections are caused by bacteria. Staphylococcus is a common bacterium that causes skin infections. Treatment includes topical, oral, or intravenous antibiotics. Severe infections may require drainage of the infected wound and hospitalization. The following are common antibiotics used to treat bacterial infections.                                                                                                                                                                                1) Azithromycin (Zithromax)                                                                                                                                                                                                            2) Bacitracin (Bacitracin)                                                                                                                                                                                                                    3) Bacitracin/Neomycin/Polymyxin B (Neosporin, Triple Antibiotic)                                                                                                                                            4) Cephalexin (Keflex)                                                                                                                                                                                                                          5) Ciprofloxacin (Cipro)                                                                                                                                                                                                                        6) Mupirocin (Bactroban)                                                                                                                                                                                                                    7) Vancomycin (Vancocin)  Fungal infections are caused by fungi. Athlete's foot is a common fungal infection. Skin surfaces that are exposed to sweat, such as abdominal folds, feet, and armpits, are at higher risk of acquiring fungal infections. Fungal infections are treated with antifungal medications. The following are some common antifungal medications:                                                                                                                                                                   1) Nystatin (Nystop)                                                                                                                                                                                                                             2) Fluconazole (Diflucan)                                                                                                                                                                                                                     3) Miconazole (Lotrimin)                                                                                                                                                                                                                     4) Terbinafine (Lamisil)                                                                                                                                                                                                                         5) Amphotericin B (Ambisome) Viral infections are caused by viruses. Chicken pox, shingles, and genital warts are common viral infections. Viral infections are highly contagious and sometimes require isolation. Genital warts may spread through sexual contact. Viral infections are difficult to treat, and sometimes patients are provided supportive care until the infection runs its course. Viral infections are treated with antiviral medications. The following are some common antiviral medications:                                                                                                                                                                       1) Acyclovir (Zovirax)                                                                                                                                                                                                                             2) Valacyclovir (Valtrex)                                                                                                                                                                                                                       3) Famciclovir (Famvir)                                                                                                                                                                                                                         4) Ganciclovir (Cytovene)                                                                                                                                                                                                                     5) Cidofovir (Vistide) Parasitic infections are caused by parasites. Pediculosis and scabies are common parasitic infections. The following are some common medications to treat parasitic infections:                                                                                                                                                                                         1) Lindane (Kwell)                                                                                                                                                                                                                                 2) Permethrin (Elimite)                                                                                                                                                                                                                         3) Crotamiton (Eurax)   Skin Lesions Infections, allergic reactions, and trauma to your skin can cause skin lesions. The Primary Skin Lesions table lists commonly used terms related to the appearance of primary skin lesions.  Primary Skin Lesions Abrasion | The scraping away of epidermal tissue Contusion | Injured skin that's intact and not broken Cyst | A hollow cavity filled with liquid secretions Excoriation | The superficial loss of tissue due to trauma, chemicals, or burns Laceration | Broken skin layers or torn flesh Macules | Non-palpable discolored spots or patches Papules | Small, solid, circumscribed (rounded), raised areas. Examples include warts, moles, and pimples. Polyp | A small growth protruding from a mucous membrane Pustules | Small, elevated, circumscribed, pus-containing lesions  Vesicles | Blister-like elevations containing serious fluid. Examples include lesions due to dermatitis, burns, chicken pox, and scabies. Wheals | Localized areas of edema on the body surface. Examples include urticaria, or hives from an allergic reaction.   Secondary skin lesions result from the healing process. As a primary skin lesion heals, scabs or crusts form over the affected area. These secondary lesions are composed of dry pus, lymph, or blood and may vary in color and thickness. Select each tab to learn about the terms related to the appearance of the secondary skin lesions. Cicatrix is a scar from a wound that has healed. Hypertrophied is a firm, raised, and thickened condition of a scar. Keloid is a progressively enlarging, irregularly shaped scar tissue due to excessive collagen formation in the corium during tissue repair.   Skin lesions are usually treated with topical corticosteroids, antibiotics, and antiseptics, depending on the type of skin lesion. The following is a list of common corticosteroids that are available to treat various skin disorders: Betamethasone (Diprolene, Valisone) Clobetasol (Temovate) Desonide (Desowen) Desoximetasone (Topicort) Fluocinolone (Capex) Hydrocortisone (Cortef) Triamcinolone (Kenalog)   Pressure Ulcers An ulcer is an open sore or lesion caused by trauma, intense heat or cold, pressure, or bacterial infection. An ulcer is a depression of the epidermis. It can progress to the erosion of the skin layers. Pressure ulcers (or decubitus ulcers) are specifically caused by direct pressure due to prolonged immobility. When someone is sitting or laying down for long periods, ulcers may occur at the points that bear the most pressure, such as the heels, tailbone (coccyx), elbows, and the back of the head. Patients that are immobile due to stroke, coma, or other serious diseases are at the greatest risk for developing pressure ulcers. Once an ulcer has formed, it doesn't heal unless aggressive measures are taken to relieve the pressure. The ulcers may require surgery to remove dead or infected tissue.   Pressure ulcer treatment includes keeping the affected area clean and dry. Antibiotics, steroids, and pain reliever medications are sometimes used to provide symptomatic relief, decrease the inflammation, and treat infection if present. Pressure ulcers are classified into four stages based on severity.  Stage 1: Stage I ulcers have reddened skin, but the skin isn't broken. Stage 2: Stage II ulcers can have broken or unbroken blisters that are reddened and/or irritated.  Stage 3: Stage III ulcers have skin breakage through all layers. Stage 4: Stage IV ulcers go through all layers of skin and can affect muscles, tendons, and even bone.   Inflammatory Skin Disorders Dermatitis is a general term referring to any inflammation of the skin. Dermatitis isn't always caused by infections. Eczema and psoriasis are the most common inflammatory skin conditions. Eczema, also known as atopic dermatitis, is a common inflammatory disorder in which skin patches become rough and swollen with blisters. Eczema is more prevalent in children but may persist into adulthood in some cases. Common symptoms of eczema include itching, dryness, redness, and swelling. In most cases, the cause of eczema is unknown but can be triggered by conditions such as allergies and asthma. Eczema may also be triggered by humidity, infection, or stress. Eczema may be prevented by avoiding or minimizing exposure to the allergens, keeping the skin clean and moisturized, and drinking plenty of fluids to stay hydrated. Treatment of eczema includes topical corticosteroids, antihistamines, and immunosuppressant agents.          Drug Class: Topical Corticosteroids   Generic Name                                   Brand Name Hydrocortisone                                   Cortef Triamcinolone                                     Kenalog Clobetasol                                           Temovate Desoximetasone                                Topicort            Drug Class: Oral Antihistamines   Generic Name                                  Brand Name Diphenhydramine                             Benadryl Cetirizine                                             Zyrtec  Fexofenadine                                     Allegra Loratadine                                          Claritin                    Drug Class: Topical Antibiotics   Generic Name                                            Brand Name    Mupirocin                                                     Bactroban                                   Sulfacetamide                                              Klaron Bacitracin/Neomycin/Polymyxin B           Neosporin, Triple Antibiotic     Drug Class: Topical Immunosuppressants   Generic Name                                   Brand Name Tacrolimus                                           Protopic Pimecrolimus                                      Elidel     Psoriasis is a chronic skin disorder that results from overproduction of the skin cells. It's characterized by plaque formation on the skin surface due to the accumulation of the rapidly growing skin cells. The plaque may appear red, dry, and covered with silvery scales. Elbows, wrists, and knees are some of the most commonly affected areas. Psoriasis can occur at any age but is most common between the ages of 15 and 30. Mild psoriasis is treated with topical corticosteroids, vitamin D derivatives, and retinoids. Severe forms of psoriasis generally require oral and injectable immunosuppressant medications. The medications commonly used to treat psoriasis are listed below by drug class.    Drug Class: Vitamin D Derivatives   Generic Name                      Brand Name Calcipotriene                          Dovonex   Drug Class: Retinoid   Generic Name                    Brand Name Tretinoin                               Retin-A    Drug Class: Systemic Immunosuppressants   Generic Name                  Brand Name Methotrexate                     Trexall Cyclosporine                      Neoral, Sandimmune         Drug Class: Other Drugs   Generic Name             Brand Name Efalizumab                     Raptiva Etanercept                     Enbrel Adalimumab                 Humira     Burns Burns are common, but they can cause serious problems that affect the skin. Burns occur from overexposure to heat, chemicals, electricity, or radiation. Burns are classified according to their severity. The classification is made by determining the number of tissue layers involved. 1) First-Degree Burn.  A first-degree burn is a minor burn. Although there may be some redness and discomfort, blistering usually doesn't occur and little tissue is destroyed. First-degree burns are labeled as superficial burns. If blisters do form, the upper layers of the epidermis may peel within one to three days. Healing usually takes about a week. 2) Second-Degree Burn. A second-degree burn causes injury to the top layers of the dermis. Second-degree burns are labeled as partial-thickness burns. Although these burns damage sweat glands, hair follicles, and sebaceous glands, the dermis isn't completely destroyed. A second-degree burn is characterized by blisters, severe pain, generalized swelling, and fluid loss and usually results in scarring. Healing takes about two weeks. 3) Third-Degree Burn. Third-degree burns are the most severe and generally cause no pain at first because of the damage to the nerve endings. In this type of burn, the epidermis and dermis have been completely destroyed, and the damage extends below the dermis into the subcutaneous layer. Third-degree burns are labeled as full-thickness burns, wherein the damage goes into the fat, muscle, and bone. Someone with third-degree burns has a high risk of infection from loss of the protective skin layers and may experience a loss of bodily fluids. Third-degree burns usually require skin grafting—a type of surgery in which the burned skin is removed and replaced with skin from another location. However, the larger the surface area affected by the burn, the greater the risk of complications or death. 4) Treatment Options for Burns. A first-degree burn usually requires no treatment and heals on its own. A second-degree burn may require topical antibiotics such as silver sulfadiazine (Silvadene) or pain relievers. Severe burns require hospitalization, skin grafting, hydration, and intravenous antibiotics.   Acne Acne is a common skin disorder among adolescents and young adults. There are multiple factors that cause acne, such as abnormal epithelial cell growth in puberty, increased production of sebum (oil) by sebaceous glands, infections, and inflammations. There are also many options to prevent and treat acne, including antibacterial washes, creams, and gels. Retinoic agents are also used for the treatment of severe acne. Other agents used to treat acne include keratolytics, corticosteroids, and anti-inflammatory agents. The acne medications commonly used to treat acne are listed in each tab by drug class.      Drug Class: Topical Antibiotics   Generic Name                   Brand Name Benzoyl Peroxide               Benzac, Clearasil Clindamycin                       Cleocin, Clindagel, Clindamax Erythromycin                     Erygel, Akne-Mycin Sulfacetamide                   Klaron, Ovace       Drug Class: Retinoic Acid   Generic Name              Brand Name Isotretinoin                     Accutane  Tretinoin                          Retin-A Tazarotene                      Tazorac     Drug Class: Keratolytic Agents   Generic Name             Brand Name Salicylic acid                   Multiple brand names     Key Points Skin infections are caused by bacteria, viruses, fungi, and parasites. An allergic reaction can cause symptoms of rash, itching, and hives on the surface of the skin and is commonly treated with antihistamines and corticosteroids. Eczema is more common in children and can be triggered by various environmental factors. A combination of steroids, antibiotics, antihistamines, and immunosuppressant drugs are available to treat eczema. Third-degree burns are the most severe and require emergency treatment and hospitalization.                          

Introduction The aging process has a significant effect on bones, joints, and muscles. As you age, the number and function of your bone cells decline—as well as the amount of cartilage in your body, the flexibility of your joints, and the function of your muscles. As the muscle tissue diminishes, it's replaced by fibrous tissue that can't contract appropriately. Thus, the overall strength of muscle declines with age. Many musculoskeletal diseases are the result of physical injury and aging. Balanced nutrition, vitamin supplementation, and regular exercise can help prevent many musculoskeletal disorders.   Injury Disorders Muscles and joints are at a high risk of wear and tear due to daily activities. Overuse of certain muscle groups and performing high-impact activities may also result in injury to your muscles, joints, and tendons. An accident or trauma may cause injury to musculoskeletal organs. The most common type of musculoskeletal injuries are strains, sprains, and spasms. A strain is a tear in a tendon or muscle fiber as a result of overstretching a muscle. Strains usually result from an injury or vigorous exercise without appropriate stretching. The tearing of tendons may result in internal bleeding and bruising. Pain and inflammation may also result at the site of an injury when the muscle is contracted. Preventative measures for strains include careful stretching before and after exercise and gradually warming up intense exercise. It should be noted that a muscle strain isn't the same as a joint sprain.   A sprain is a tear in a ligament as a result of trauma or due to the joint being twisted beyond its normal range of motion. Based on the severity of the injury or trauma to the affected joint, one or more ligaments can be damaged or torn. Ankle and wrist joints are at the highest risk of sprains. A sprained joint, if severe, may require surgical repair and may result in prolonged immobility.  A spasm or cramp is a condition characterized by the undesired, prolonged contraction of a muscle. Spasms can range from painless to extremely painful and can occur after vigorous exercise. For example, you might get calf cramps after playing basketball for too long. Muscle spasms can accompany a joint or bone problem because the surrounding muscles are forced to contract constantly to compensate for any joint dysfunction.   Treatment of musculoskeletal injuries is decided based on the type and severity of the injury. Minor injuries may only require an ice pack to the affected area or over-the-counter pain relievers or anti-inflammatory medications. Severe injuries may require surgical intervention, prolonged immobility, stronger prescription pain medications, and antibiotics.   Bone Disorders Osteomyelitis Osteomyelitis is the infection inside a bone. It's a common complication for diabetes patients with foot infections. Inflammation can reduce the blood supply to the bone, resulting in bone necrosis. Necrosis is the process of tissue death that may require amputation of the affected bone. The symptoms of osteomyelitis are pain or tenderness in the affected area, inflammation, redness, and a high fever. Osteomyelitis requires an intense treatment of intravenous antibiotics in high doses and for a long duration. Severe cases may require surgery to clean out the dead bone tissue in addition to antibiotics. Patients are also prescribed medications to reduce pain and swelling. Common antibiotics used to treat osteomyelitis are: Cefazolin (Kefzol, Ancef) Daptomycin (Cubicin) Linezolid (Zyvox) Vancomycin (Vancocin) Osteoporosis Osteoporosis is a condition characterized by a decrease in total bone mass. Bones are comprised of 50 percent water and 50 percent solids. Vitamins and minerals make up over half of the solid material, and the rest is white fibrous tissue. Healthy bone breaks down old tissue and manufactures new tissue to replace it. In osteoporosis, the new tissue isn't manufactured fast enough to replace the old one. Consequently, the bones become soft and weak. Osteoporosis most commonly occurs with growing age. However, the disease may also result due to prolonged immobilization, hormonal disorders, and a diet low in protein and calcium. An inadequate amount of calcium and phosphorus in the blood can cause bones to become soft and deformed. Estrogen is also an important hormone to maintain healthy bones. In postmenopausal women with decreased estrogen levels, osteoporosis is the major factor leading to frequent fractures. In the elderly, bones become thin and abnormally porous, causing bones to break or fracture easily and spontaneously. The disease is asymptomatic but may cause "shrinking" to the body. In other words, the elderly affected by severe osteoporosis may appear shorter, with rounded shoulders. Osteoporosis Treatment The following are some common medications used in the treatment of osteoporosis: Alendronate (Fosamax) Calcitonin (Miacalcin) Calcium with vitamin D (OsCal D) Conjugated estrogen (Premarin) Ibandronate (Boniva) Medroxyprogesterone (Provera) Raloxifene (Evista) Risedronate (Actonel) Bone Marrow Depression Bone marrow depression decreases the number of red blood cells (RBCs), white blood cells (WBCs), and platelets. Bone marrow depression is a serious adverse reaction linked to many drugs, especially antihistamines, tranquilizers, chloramphenicol (Chloromycetin), phenylbutazone (Butazolidin), sulfonamides, antineoplastics, thyroid medications, antidepressants, and diuretics. Symptoms of bone marrow depression include weakness, pale skin, dyspnea, soreness of mucous membranes, fever, chills, extreme fatigue, urinary and vaginal infections, and bleeding. Severe bone marrow depression may require blood transfusions. If a medication is identified to be the cause of the bone marrow depression, symptoms usually resolve once the offending medication is discontinued. Patients are often given intravenous antibiotics until a normal blood level of WBCs is attained.   Joint Disorders The term arthritis means "inflammation of a joint." The symptoms of arthritis are persistent pain, inflammation, and stiffness, especially in the morning. There are various forms of arthritis, such as rheumatoid arthritis, osteoarthritis, and gouty arthritis. 1) Rheumatoid arthritis, the most serious and crippling form of arthritis, is a systemic autoimmune disease that gradually affects more and more joints as time passes. Your body's own immune system starts attacking the joint tissue. Anti-inflammatory medications are somewhat effective when taken in higher prescription doses. The symptoms of rheumatoid arthritis are loss of appetite, a general feeling of being ill, weight loss, and muscular pain. As the joints become more affected, they become red, swollen, tender to the touch, and painful to move. 2) Ankylosing spondylitis is an inflammation of the joints that link the vertebrae in the spine. As the inflammation recedes, it leaves the joints hardened and damaged. The symptoms of ankylosing spondylitis are a lower backache that may spread to the buttocks; stiff, painful hips; vague chest pains; tenderness over the heels; and red and painful eyes. Some common medications for treatment are Adalimumab (Humira) Azathioprine (Imuran) Celecoxib (Celebrex) Cyclosporine (Neoral, Sandimmune) Hydroxychloroquine (Plaquenil) Etanercept (Enbrel) Hydrocortisone (Solu-Cortef) Infliximab (Remicade) Methotrexate (Trexall) Methylprednisolone (Solu-Medrol) Rituximab (Rituxan) 3) Osteoarthritis normally occurs due to the wear and tear of the joints. It mostly affects the elderly. It common affects weight-bearing joints such as the spine, hips, and knees. The disease causes the smooth lining of a joint—the articular cartilage—to crack and flake. As the cartilage deteriorates, the underlying bone becomes thickened and distorted. Movement becomes painful, so the muscles begin to decline from lack of use. The symptoms of osteoarthritis are episodes of pain, swelling, and stiffness in the joint area, which sometimes results in knobby-looking joints. Common medications used for treatment include Acetaminophen (Tylenol) Ibuprofen (Motrin, Advil) Naproxen (Naprosyn, Aleve) Methylprednisolone (Solu-Medrol) Prednisolone (Prelone, Deltasone) Morphine (MS Contin) Hydromorphone (Dilaudid) Oxycodone (Oxycontin) 4) Gouty arthritis is an inflammation of the joints caused by a metabolism defect. This defect results in an excessive amount of uric acid in the blood, which begins collecting in the joints and soft tissues surrounding the joints. The excess uric acid can then crystallize in the joints, tendons, and surrounding tissue, which causes extreme pain and inflammation. Gout mostly affects big toes and the adjoining areas. Common medications used to treat gout include Allopurinol (Zyloprim) Colchicine (Colcrys) Ibuprofen (Motrin) Indomethacin (Indocin) Methylprednisolone (Solu-Medrol) Sulfinpyrazone (Anturane)   Joint Dislocation When a bone is displaced from its normal position in the joint, it's called a dislocation. The usual treatment for this condition is for the bone to be returned to its proper position by gentle force, called reduction. Dislocation causes the ligaments to stretch. After reduction, rest is required so that they can heal.   Other Musculoskeletal Disorders There are other musculoskeletal disorders such as muscle pain, bursitis, and carpal tunnel syndrome. Muscle Pain: There can be many reasons for myalgia, or pain in the skeletal muscles. Muscle relaxants are the common class of medications used to treat myalgia. Commonly used muscle relaxants include: Baclofen (Lioresal) Carisoprodol (Soma) Chlorzoxazone (Parafon Forte) Cyclobenzaprine (Flexeril) Diazepam (Valium) Bursitis: is the inflammation of one or more bursae. Bursae are small sacs filled with synovial fluid, located between bones and ligaments and between bones and muscles. These fluid-filled sacs help in the smooth gliding of the tendons and muscles across bones. Inflammation or infection of the bursae may cause pain, redness, swelling, and decreased muscle movement. Common medications used to treat bursitis include: Hydrocortisone (Solu-Cortef) Indomethacin (Indocin) Naproxen (Naprosyn) Carpal tunnel syndrome is caused by tissues that swell and compress the median nerve as it runs between the ligament and the bones and tendons of the wrist (the carpal tunnel). The pinching of the nerve causes pain. The symptoms of carpal tunnel syndrome are tingling and intermittent numbness of part of the hand, pains that shoot up the wrist, and numbness or weakness of the thumb and one or more fingers. Anti-inflammatory and pain medications are commonly used to treat pain and discomfort; severe cases may require surgical manipulation of the joint.   Key Points A strain is a tear in one or more tendons. A sprain is tear in one or more ligaments. Arthritis is the inflammation of joints. Osteoarthritis is a condition that occurs due to the wear and tear of joints that comes with aging, and mostly affects weight-bearing joints such as the spine, hips, and knees. Rheumatoid arthritis is a systemic inflammatory disease, which results in the destruction of joints, causing joint deformities. Osteomyelitis is a bone infection and requires antibiotics in high doses for a long term to treat the infection.        

Lesson 2 Overview In this lesson, you'll learn the basic components, functions, and diseases of sensory organs and the nervous system. Sensory organs include general sensory receptors as well as special organs, such as the eyes, ears, nose, and tongue. Sensory organs enable you to see, hear, smell, and taste. General sensory receptors throughout your body enable you to feel pressure, pain, touch, vibration, and changes in temperature. The nervous system comprises the brain, the spinal cord, and a vast network of nerves. The nervous system controls all of your bodily functions as well as all voluntary and involuntary movements in your body. This lesson will help you gain knowledge of various diseases and treatment options related to sensory organs and nervous system diseases, including psychiatric disorders. While discussing treatment of these disorders, you'll learn about the medications used to treat each disorder. Medications listed throughout this unit are listed as generic names with brand names provided in parenthesis.    Lesson Objectives Illustrate various sensory organs, common diseases, and treatment options Explain the basic anatomy and physiology of the nervous system Describe common nervous system diseases and psychiatric disorders along with treatment options   Introduction The senses are divided into two groups: general sense organs and special sense organs. Sensory organs include general sensory receptors as well as special organs, such as the eyes, ears, nose, and tongue. Sensory organs enable you to see, hear, smell, and taste. General sensory receptors throughout your body enable you to feel pressure, pain, touch, vibration, and changes in temperature.   General Sense Organs The general sense organs are the tactile receptors, the temperature receptors, the pain receptors, and the proprioceptors. General sense organs enable you to experience touch, pressure, vibration, pain, changes in temperature, and muscle stretch. The receptors for these senses are spread throughout the integumentary system of your body and within some of its internal organs. Tactile Receptors  Tactile receptors bring you information about pressure, touch, and vibration. They're located throughout your skin but are more abundant in areas such as the fingertips and the lips. Temperature Receptors Temperature receptors enable you to sense changes in temperature. Although they're found throughout the body, they're concentrated in the lips, the mouth, and the anus. Pain Receptors Pain receptors are located throughout the skin and within certain internal organs. Some organs, however, are poorly supplied with pain receptors, making it difficult for you to determine where it actually hurts. An example of that is a headache; headaches can be felt due to the pain in the brain, the skull, the neck, or the blood vessels. Proprioceptors These enable you to sense the position of various body parts without looking and to sense whether the body parts are moving and in what direction. This sense of positioning is called proprioception, or kinesthesia. The receptors are located within muscles, joints, and tendons. Once the receptors detect a stimulus such as pain, pressure, or touch, the stimulus is converted into an electrical signal or a nerve impulse. The signal then travels the nerve pathways to the brain, where the sensation is interpreted. After the brain interprets the stimulus, it sends orders back along the nerve pathways to the organs and/or other muscles to react appropriately to the receptor.   Special Sense Organs The special sense organs are the eyes, the ears, the nose, and the taste buds. The special senses are touch, vision, hearing, smell, and taste. Touch is mediated through the integumentary system. The remaining senses are mediated by the eyes, the ears, the nose, and the tongue.  These organs receive sensory signals and transmit to the brain by way of the cranial nerves. Although sensory organs don't appear to be similar to nerves, they can be considered appendages of the nervous system. Each of these organs has unique sensory cells that pick up data and then transmit it to the brain for decoding of the collected data. (5 senses: smell, sight, hearing, taste, touch)   The nose can detect about 10,000 different smells. A highly specialized connection of nervous tissue, the olfactory bulb, or olfactory epithelium, enables your nose to smell. The part of the brain that analyzes scents works closely with memory and emotion. That's why the sense of smell can evoke powerful feelings and memories. Olfactory nerves are never replaced; once they're damaged, the sense of smell is impaired forever. They also tire quickly, which explains why a pungent odor seems to dull after it has been sensed for a while.   The tongue is the only skeletal muscle that also has sensory capability. Your tongue helps you speak, moves food around as you chew, and molds food into a ball—or bolus—for swallowing. Its surface is covered with visible, bumpy, hair-like projections called papillae. Clusters of taste buds surround the papillae and also cover the roof of your mouth. The taste buds themselves aren't visible. For a taste to be stimulated, the food must be solubilized. The mouth does this by providing saliva through the salivary ducts. The stimulus of food prompts the ducts to release saliva so the food can start to be dissolved. Specialized cells in the taste buds, gustatory cells, then detect the basic sensations of sour, salty, bitter, and sweet. The information is then converted to impulses and transmitted to the brain. The sweet and salty tastes are sensed mainly at the tip of the tongue. The sour taste is sensed at the sides of the tongue, and the bitter taste is sensed at the back of the tongue.   Common Eye Disorders and Treatments - Glaucoma is a diseased caused by increased pressure in the eye, which results in a damaged optic nerve. Increased pressure may be caused by factors such as high blood pressure, obesity, migraines, and heredity. Since there are usually no symptoms until there's a decrease in vision, annual eye exams are extremely important to detect this disease during the early stages. If untreated, glaucoma can lead to blindness. The most common form of glaucoma is called open-angle glaucoma. Open-angle glaucoma is treatable with medications, Lasik, and surgery.  The following eyedrops are commonly used to treat glaucoma: Pilocarpine (Isopto Carpine) Carbachol (Isopto Carbachol) Latanoprost (Xalatan) Travoprost (Travatan) Timolol (Timoptic) Dorzolamide (Trusopt) Betaxolol (Betoptic) Acetazolamide (Diamox) - A cataract is a cloudiness of the eye's lens due to increased age. This disease may be caused by trauma or radiation exposure. Symptoms include blurred vision, faded colors, and sensitivity to light. Common risk factors include increased age, diabetes, smoking, prolonged exposure to sunlight, and alcohol. A mainstay of the cataract treatment is the surgical removal of the cataract lens and replacement with a new lens. Cataract surgery is a minor outpatient surgery performed routinely to treat cataracts. Medicated eyedrops are normally used prior to surgery to dilate the pupils and post-surgery for inflammation and infection. Eyedrops that dilate pupils are called mydriatic medications. The following is a list of mydriatic medications: Tropicamide (Mydriacyl) Atropine (Isopto Atropine) Cyclopentolate (Cyclogyl) Phenylephrine (Mydfrin) The following eyedrops are used for inflammation and infection: Bacitracin, Neomycin, and Polymyxin B (Polysporin) Ketorolac (Acular) - Conjunctivitis, or the inflammation or irritation of the conjunctiva, is the most common infection of the eye. Conjunctivitis is also referred to as "pink eye." The infection can be caused by a virus, bacteria, or an allergen. The common cold, an upper respiratory infection, or a sore throat may lead to conjunctivitis. Symptoms include swollen, scratchy, red, and extremely watery eyes. The following antibiotic eyedrops are commonly used to treat "pink eye" or conjunctivitis: Ciprofloxacin (Cipro) Ciprofloxacin and dexamethasone (Ciprodex) Tobramycin (Tobrex) Trimethoprim/polymyxin (Polytrim)   Common Ear Disorders and Treatments Ear infections  Outer ear infections are called external otitis, and middle ear infections are called otitis media. External otitis is often referred to as "swimmer's ear." Otitis media is a common type of ear infection in children that's often treated with oral antibiotics. Earwax If your ear produces too much cerumen or earwax, it can collect in the auditory canal. When this happens, the cerumen absorbs or blocks the passage of sound waves. This blockage impairs hearing. Treatment for this includes irrigation of the ear canal and the use of lubricating drops. Carbamide peroxide (Debrox), over-the-counter (OTC) eardrops, is commonly used to remove excess earwax.    Summary Eye medications are available in various dosage forms including solution, suspension, ointment, or gel. Your eye is a sterile environment requiring sterile preparations that are instilled in the eye to treat various disorders. However, ear medications are non-sterile. It's very important to keep eye and ear medications separate.  Do not use eardrops in eyes. You must label an eye medication with a 28-day expiration date once it has been opened and exposed to the non-sterile environment. Discard eyedrops after they've been opened for 28 days. Wash your hands before instilling eyedrops or eardrops. Eardrops may be painful if instilled as a cooled solution in the refrigerator. The Commonly Used Ear Medications and Commonly Used Eye Medications tables list the commonly used ear and eye medications.                                                     Commonly Used Ear Medications   Generic Name                                                                  Brand Name                              Indication Ciprofloxacin                                                                      Cipro                                             Antibiotic Ofloxacin                                                                             Floxin                                            Antibiotic                                                                                   Neomycin, Polymyxin B, and Hydrocortisone              Cortisporin OTIC                         Antibiotic and Inflammatory Ciprofloxacin + dexamethasone                                     Ciprodex OTIC                             Antibiotic and Inflammatory Carbamide Peroxide                                                         Debrox                                         Earwax removal                                                                  Commonly Used Eye Medications   Generic Name                                                                                    Brand Name                                                 Indication Olopatadine                                                                                          Patanol                                                           Allergic conjunctivitis Ciprofloxacin                                                                                         Cipro                                                               Antibiotic Neomycin, Polymyxin B, and Gramicidin                                         Neosporin                                                      Antibiotic      Bacitracin, Neomycin, and Polymyxin B                                           Polysporin                                                      Antibiotic Neomycin, Polymyxin B, and dexamethasone susp./oint             Maxitrol                                                          Antibiotic and steroid anti-inflammatory Diclofenac                                                                                              Voltaren                                                         Anti-inflammatory Ketorolac                                                                                                Acular                                                             Anti-inflammatory Bacitracin ointment                                                                                                                                                      Blepharitis                                                       Polyvinyl alcohol + Providone                                                            Refresh Eyes                                                  Dry and itchy eyes Polyvinyl alcohol                                                                                  Artificial Tears                                                Dry eyes Brimonidine                                                                                          Alphagan                                                        Glaucoma Dorzolamide + Timolol                                                                        Cosopt                                                            Glaucoma                                  Dorzolamide                                                                                         Trusopt                                                           Glaucoma Acetylcholine solution                                                                         Miochol-E                                                       Glaucoma Pilocarpine                                                                                            Isopto Carpine                                               Glaucoma                                                      Cyclosporine                                                                                         Restasis                                                         Immunosuppressant, increase tear production Mineral Oil + Petrolatum                                                                    Lacri-Lube drops/ointment                        Lubricant Atropine drops/ointment                                                                                                                                           Mydriasis (pre-procedure) Tropicamide                                                                                         Mydriacyl                                                       Mydriasis (pre-procedure) Tetrahydrozoline                                                                                 Visine                    Mydriasis (pupil dilation, vasoconstriction, and relieving inflammation Oxymetazoline                                                                                    OcuClear              Mydriasis (pupil dilation, vasoconstriction, and relieving inflammation       Key Points Your body's composed of general sense receptors spread throughout the integumentary system and other body organs to sense pain, temperature, vibration, and touch. The eyes, the ears, the nose and the tongue are special sensory organs that help you to see, hear, smell, and taste. Glaucoma and cataract are common eye disorders. Glaucoma is caused by increased pressure in the eye, and cataract is due to cloudiness of the eye's lens. It's important not to mix eye drops with ear drops. Anything going into the eyes must be sterile. Label opened vials of eye drops with a 28-day expiration date from the date it's opened.              

Introduction The nervous system is the most sophisticated and complex body system because it regulates and coordinates the rest of your body systems. It controls every function of your body. Some of these functions are voluntary, such as running, jumping, and climbing. Other functions are involuntary, such as breathing, digesting, and pumping blood. But no matter what the function is, all of your body systems depend on the nervous system. The nervous system is mainly composed of the brain, spinal cord, and nerves. The brain and the spinal cord are referred to as the central nervous system (CNS) and nerves make up the peripheral nervous system (PNS).    Central Nervous System The central nervous system earned its name from its central location in your body, a good location for a system that functions as the communication headquarters. Whether you're awake or not, the central nervous system continuously receives information, makes decisions, and sends information to nerves located throughout your body.   The central nervous system contains the two most important structures in the body—the brain and the spinal cord. These delicate structures are vital to our survival, and therefore have two coverings—an outer covering of bone and an inner covering of membrane. Two types of bone form the outer covering:  1. The cranial bone, which encases the brain 2. The vertebrae, which encase the spinal cord Three distinct layers of tissues, also known as meninges, form the inner covering: 1. Dura mater—a tough outside layer 2. Arachnoid mater—a web of delicate fibers connecting dura mater to pia mater 3. Pia mater—a soft and tender inside layer   In addition to protecting the brain and the spinal cord from injury, the meninges allow nourishment to pass through a complex channel system. The dura mater is a thick, tough membrane that contains channels for blood to pass into the brain tissue. The subdural space below the dura mater contains many blood vessels that carry nourishment to the tissue. Between the arachnoid mater and the pia mater is another space called the subarachnoid space, and this space contains the cerebrospinal fluid. The pia mater layer is made of connective tissues and a rich supply of blood vessels.   Cerebrospinal fluid (CSF) is a built-in shock absorber for the central nervous system. This colorless fluid circulates around and within the brain through the ventricles (cavities in the brain), the central canal of the spinal cord, and the subarachnoid space. The ventricles and the meninges form a dynamic system that regulates the amount of CSF covering the brain. The ventricles produce the fluid which is reabsorbed by the meninges to prevent buildup of excess fluid. Therefore, the meninges and the cerebrospinal fluid not only form a physical layer of protection for the brain but also serve a circulatory role by providing nutrients and removing waste products. The CSF is produced by a collection of blood vessels called the choroid plexus, located within each ventricle. These blood vessels also perform a special function within the brain. They help form what's known as a blood cerebrospinal fluid brain barrier (BCSFB). This barrier helps protect the brain by controlling which substances enter and leave the brain.   Your spinal column is the characteristic that qualifies you as a vertebrate. Inside the spinal column lies the spinal cord, a slightly hollow cylinder of neural tissue, which is attached to the brain stem. Gray matter composes its inner section. The white matter, which composes its outer region, contains sensory and motor neurons to transmit nerve impulses to and from the brain. The spinal cord begins at the medulla and continues down the vertebral column to the level of the second lumbar vertebra. At the lower end of the spinal column is the cauda equina, which is a collection of nerve roots.  Like the brain, the spinal cord is encased by the three meninges as well as cerebrospinal fluid. The spinal cord sends out 31 pairs of spinal nerves to connect to the peripheral nervous system.  The main function of the spinal cord is to send sensory input to the brain and receive motor output from the brain. Thus, damage to the spinal cord may affect the function of skeletal muscles even if the brain isn't affected. The spinal cord processes some signals without the involvement of the brain. These signals are responsible for primitive reflexes such as the blinking or sneeze reflex.   Peripheral Nervous System The main function of the autonomic nervous system is to regulate the function of the cardiac muscles and the smooth muscles, including those in the digestive, respiratory, urinary, reproductive, and endocrine systems. The autonomic nervous system is further divided into the sympathetic and the parasympathetic nervous systems.  Sympathetic Nervous System This division is involved in "fight or flight" reactions which occur in a split second before the brain can consciously think about it. It kicks into high gear during stressful situations, preparing your body for physical and/or emotional conflict. Survival instincts depend on this "fight or flight" response and this response deals with the concept to fight or flee from a situation. Everyday life provides opportunity for the sympathetic nervous system to operate. If you're walking across the street and see a car coming toward you, you suddenly jump out of the way. Then you notice your heart pounding in your chest. This reaction is the result of the sympathetic nervous system. An increased heart rate is necessary for increased skeletal muscle activity. Parasympathetic Nervous System The parasympathetic division of the autonomic nervous system counterbalances the action of the sympathetic nervous system. The parasympathetic nervous system provides a calming counterbalance to the sympathetic nervous system by exerting opposite effects on internal organs (for example, slowing down heart rate). The parasympathetic nervous system is important for stability so that your body can proceed with normal activity. Thus, the parasympathetic nervous system activates the muscles of the digestive tract to allow digestion, a process that's unimportant during stressful situations but vital to prolonged health. Sympathetic and Parasympathetic  When a person is in perfect health, the sympathetic and parasympathetic nervous systems are balanced. Overactivity of either system can cause problems. High levels of stress, which stimulate the sympathetic system, may contribute to the development of heart disease and heart attacks. On the other hand, an unopposed action of the parasympathetic system may cause the heart rate to slow down and the blood vessels to dilate too much, causing a drop in blood pressure.   Neurons The neuron, or nerve cell, is the basic unit of the nervous system. Its sole purpose is to conduct signals from one end of the nervous system to the other. The human body operates smoothly because hundreds of nerves communicate with the central nervous system. Neurons are divided into three major structures: dendrites, cell body, and axon.    Dendrites pick up signals and send them to the body of the nerve cell. The neuron cell body nourishes the neuron. In peripheral nerves, the cell body may even grow new fibers when the old ones are cut or torn. Groups of cell bodies are called ganglions. The single axon sends the impulse from the cell body to a muscle, gland, or another nerve cell. Bundles of axons make up nerves. Think Of This Analogy Your fingers are the dendrites, your hand is the cell body, and your arm is the axon. All five fingers pick up sensory information, which is then relayed to your hand and up your arm. Peripheral nerves are discrete structures large enough to be seen with the naked eye. Each nerve contains a large number of fibers, which are the axons or dendrites of the neurons.   Sensory nerves are afferent nerves. Afferent means to carry something toward a center. These nerves receive information from the sense organs—the ears, eyes, nose, tongue, and skin—and send that information to the brain. Motor nerves are efferent nerves, meaning to carry something away from the center. These nerves receive orders from the central nervous system and carry the orders out. Mixed nerves contain both sensory and motor nerves. Most of the peripheral nerves that connect with the rest of the body are mixed nerves because they perform both sensory and motor functions. For example, the femoral nerve allows you to both feel sensations on your thigh and move it. Myelin is a fatty white substance that covers many of the axons in the central and peripheral nervous systems. You can think of myelin as an insulator because it keeps other nearby nerves from being affected by impulses. The myelin sheath also accelerates signal transmission along the axon. Certain diseases affecting the myelin sheath can hinder or slow down the conduction of signals in the nervous system.  The synapse is the tiny space between neurons. Chemical substances called neurotransmitters help the impulse cross the synapses and travel from axon to dendrite. Neuroglia, the only other type of nerve cell beside neurons, literally means "nerve glue." Neuroglia cells serve to support, protect, and nourish the neurons and anchor them to the blood vessels.   Key Points The central nervous system is comprised of the two most important structures in the body: the brain and the spinal cord. The peripheral nervous system is comprised of the spinal and cranial nerves. The cerebrum is the major part of the brain that's divided into two hemispheres (right and left). The right hemisphere controls the body actions of the left side of the body; the left hemisphere controls the body actions of the right side of the body. The brain stem is a vital part of the brain because it connects the brain to the spinal cord and all nerve messages pass through the brain stem to the body. The main function of the spinal cord is to send sensory input to the brain and receive motor output from the brain.      

Introduction Nervous system and psychiatric diseases include many complicated disorders involving nerve transmission, neurotransmitters, mood and behavior, and sensory and motor impulse disturbances. The medical specialty of neurology diagnoses and treats nervous system disorders. Psychology and psychiatry diagnose and treat psychiatric diseases. Some nervous system and psychiatric diseases are difficult to diagnose in early stages and may cause severe impairment and long term damage if left untreated. Many medications are available to treat these disorders, but a combination of psychotherapy and behavioral therapy produce the best results in treating behavioral disorders.    Nervous System Disorders and Treatments Because the nervous system is so complex and fragile, it's vulnerable to various disorders. Nervous system disorders may be caused by functional impairments, brain tissue degeneration, vascular abnormalities, trauma, or infections. Aging plays a role in decreased nerve signal reception and conduction. This results in varying degrees of decreased vision, hearing, muscle coordination, confusion, and weakness. Some of the common symptoms of nervous system disorders include tremors, blurred vision, paralysis, irritability, change in respiration and pulse, restlessness, and speech difficulties.   Parkinson's disease is a slowly degenerative disease caused by shrinking levels of the neurotransmitter dopamine. It may result from the loss of dopamine-producing neurons in the brain.   Dopamine is a neurotransmitter vital for the normal functioning of posture control, physical support, and voluntary movement. Causes of Parkinson's disease are unknown, and there's no cure. Medications are used to relieve symptoms of the disease.  The following are four hallmark signs of Parkinson's disease: 1. Resting tremor (shakiness in hands and feet) 2. Muscular stiffness or rigidity  3. Slowing of movements (bradykinesia) 4. Impaired postural reflexes (the most debilitating because it increases the risk of falls)   The following medications are used to relieve Parkinson's disease symptoms: Levodopa/Carbidopa (Sinemet) Entacapone (Comtan) Entacapone/Levodopa/Carbidopa (Stalevo) Benztropine (Cogentin) Rasagiline (Azilect)   Alzheimer's disease (AD) is characterized by loss of memory, poor judgment, and general withdrawal from daily life. The exact causes of this disease are unclear. This disease can be traumatic for family members because the patient's personality changes. One important fact about AD is that it's not a normal process of aging. Early warning signs of Alzheimer's disease include memory loss, difficulty performing familiar tasks, speech impairment, disorientation, and significant mood or behavior changes.  The following medications are commonly used to treat Alzheimer's disease: Donepezil (Aricept) Rivastigmine (Exelon) Galantamine (Razadyne) Memantine (Namenda)   Multiple sclerosis (MS) is caused by an inflammation of the myelin sheath that covers the nerve pathways in the brain and spinal cord. Once the myelin sheath is damaged, nerves are unable to conduct impulses appropriately. Causes of MS are unknown, but some believe a virus is responsible. MS is more common in women than men and occurs more frequently between the ages of 15 and 45. Although steroids and muscle relaxants may help, there's no effective treatment for MS. The symptoms of MS are tingling, numbness, and weakness affecting certain areas of the body. It may also result in loss of balance, poor coordination, shaking or tremors, muscle spasticity, difficulty in speaking clearly, and bladder dysfunction. The following medications are commonly used to treat MS: Glatiramer (Copaxone) Interferon beta-1a (Avonex) Interferon beta-1b (Betaseron) Azathioprine (Imuran) Cyclophosphamide (Cytoxan) Mitoxantrone (Novantrone) Diazepam (Valium), baclofen (Lioresal), and tizanidine (Zanaflex) are used to decrease symptoms of spasticity.    Meningitis is an inflammation of the meninges due to an infection. The infection often results from an invasion of bacteria or viruses. Because there are many forms and degrees of meningitis, treatment is tailored to the type of bacterium or virus causing the disease as well as the severity of the infection.  The symptoms of meningitis are fever, nausea, vomiting, stiff neck, inability to tolerate bright light, a deep red or purplish skin rash, drowsiness, and even unconsciousness in severe cases. Meningitis is very difficult to treat with antivirals or antibiotics due to the inability of many medications to cross the blood-brain barrier. Patients often require high doses of antivirals and antibiotics to treat meninges.  Meningitis Treatment The following antibiotics and antivirals are effective against meningitis when used with a combination of two to three medications given in high doses: Ceftriaxone (Rocephin) Cefotaxime (Claforan) Vancomycin (Vancocin) Meropenem (Merrem) Acyclovir (Zovirax) Ganciclovir (Cytovene) Myasthenia Gravis Myasthenia gravis is a rare disease that causes weakness in certain skeletal muscle groups due to faulty transmission of nerve impulses to those muscles. Symptoms include muscular weakness (initially facial), drooping eyelids, double vision, and difficulty talking and swallowing. Myasthenia Gravis Treatment The following medications are effective in treating myasthenia gravis: Neostigmine (Prostigmin) Pyridostigmine (Mestinon)   Tension headaches (or headaches in general) are probably the most common medical complaint. Headaches can be caused by stress, lack of sleep, dehydration, a side effect effect of medications, or environmental factors. A migraine is an episodic headache that's accompanied by nausea, vomiting, and sensitivity to light and sound. It's one of the most severe and debilitating types of headache. Migraines are known to be caused by a sequence of changes as a result of neural dysfunctions. Tension Headache The following medications are used in treating the common headache: Acetaminophen (Tylenol) Acetaminophen with caffeine (Excedrin) Butalbital and aspirin (Fiorinal) Butalbital and Acetaminophen (Fioricet) Acetaminophen, Isometheptene, and Dichloralphenazone (Midrin) Ibuprofen (Motrin) Migraine The following medications are commonly used to treat acute attacks as well as prevent future migraine attacks: Sumatriptan (Imitrex) Eletriptan (Relpax) Zolmitriptan (Zomig) Topiramate (Topamax) Ergotamine (Ergostat)   A stroke is known as a cerebrovascular accident or CVA. A seizure disorder is generally known as a convulsion. 1. A stroke is a sudden onset of a neurological deficit in the blood vessels that supply blood to the brain. The cause of the stroke can be due to a blood clot (thrombus) or bleeding (hemorrhage) in any part of the brain. When a blood clot or thrombus clogs a blood vessel in the brain, it results in a lack of oxygen to the affected area, causing an ischemic stroke. In other cases, various factors such as increased pressure and trauma can cause the blood vessels to burst open in the brain, causing a hemorrhagic stroke.  It's very important to distinguish these two types of strokes to choose an appropriate treatment. Common signs and symptoms of stroke include blurred vision, speech impairment, partial paralysis, dizziness, memory loss, and fainting. Hemorrhagic stroke often requires blood transfusions and immediate surgical intervention to stop the bleeding. 2. The following medications are commonly used to treat ischemic stroke: Dipyridamole (Persantine) Ticlopidine (Ticlid) Heparin sodium (Heparin) Enoxaparin sodium (Lovenox) Warfarin sodium (Coumadin) Alteplase (TPA)—Treats acute and severe ischemic stroke and must be administered within the first one to two hours of the onset of stroke symptoms for the best clinical outcome. 3. A seizure disorder is generally known as a convulsion. It's the disease of involuntary contraction or a series of contractions by voluntary muscles. Any irritation of the nerves can lead to seizures. Such irritations may cause infectious diseases such as meningitis and encephalitis.  There are many types of seizures, but regardless of the form, the seizure is caused by communication problems among the brain's nerve cells. This breakdown in communication results in a temporary disturbance of the brain's impulses. Patients may temporarily lose consciousness and have jerky movements in the skeletal muscles.  4. The following seizure medications are commonly used: Phenytoin (Dilantin) Carbamazepine (Tegretol) Levetiracetam (Keppra) Phenobarbital (Luminal) Primidone (Mysoline) Lamotrigine (Lamictal) Gabapentin (Neurontin) Tiagabine (Gabitril) Valproic acid (Depakote)   Psychiatric Disorders and Treatments Depression is a mood disorder that involves great sadness, despair, dejection, and feelings of hopelessness. Common symptoms of depression include lethargy, sleeplessness, lack of interest, isolation, and lack of motivation. Depression is caused by a decrease in the function of neurotransmitters (NTMs) responsible for controlling mood. Serotonin, norepinephrine, and dopamine are the main NTMs involved in many psychiatric disorders, including depression. Suicide is the most serious outcome of depression. Medications that are used to treat depression (antidepressants) also increase the risk of suicide. Generally, lethargy and lack of motivation are the first symptoms to respond to antidepressants, which can lead to carrying out the suicidal thoughts. All antidepressants are required to include a warning of increased suicidal risk associated with their use. Medications are used in conjunction with non-pharmacologic therapies such as behavioral therapy, light therapy, and electroconvulsive therapy (ECT) to improve the outcome. Many medications are available to treat depression.   Antidepressant Medications Drug Class                                                                       Selective Serotonin Reuptake Inhibitors (SSRIs) Tricyclic Antidepressants (TCAs) Serotonin/Norepinephrine Reuptake Inhibitors (SNRIs) Other Mechanism of Action Increase serotonin levels at the synaptic cleft. Increase both serotonin and norepinephrine levels at the synaptic cleft. Increase serotonin and norepinephrine levels by blocking reuptake  Generic Name Citalopram, Escitalopram, Fluoxetine, Paroxetine, Sertraline Amitriptyline, Nortriptyline, Clomipramine, Desipramine, Imipramine Venlafaxine, Desvenlafaxine, Duloxetine  Trazodone Bupropion  Mirtazapine  Brand Name Celexa Lexapro Prozac Paxil Zoloft Elavil Pamelor  Anafranil Norpramin Tofranil Effexor Pristiq Cymbalta Desyrel Wellbutrin Remeron   Anxiety is believed to be caused by abnormal levels of neurotransmitters such as serotonin, norepinephrine, and gamma-aminobutyric acid (GABA). Extreme anxiety, fear, or terror may result in panic disorder.  Everyone experiences some level of anxiety during stressful or fearful situations. It's the body's normal reaction. When it becomes excessive and starts affecting daily routines, it becomes a disease. Anxiety often co-exists with depression and is more common in women than men. Obsessive Compulsive Disorder (OCD) is a form of anxiety. Patients suffering from OCD become anxious and obsessive in performing certain tasks over and over in a certain order, such as hand-washing, arranging items in a certain way, or performing daily tasks in a specific order. Anxiety Symptoms Common symptoms of anxiety include agitation, tiredness, headache, stomach ache, restlessness, difficulty breathing, vomiting, excessive fear, and worry. Anxiety Treatment Even though benzodiazepine class of medications listed below are the mainstays for treating anxiety, antidepressants and sedatives are also beneficial in treatment. Alprazolam (Xanax) Clonazepam (Klonopin) Diazepam (Valium) Lorazepam (Ativan) Clorazepate (Tranxene-T) Temazepam (Restoril)   Bipolar disorder is a mood disorder similar to depression. Patients experience episodes of both mania and depression at various points in their lives. It affects both men and women equally and generally becomes apparent in patients in their twenties. Bipolar disorder is managed with a combination of pharmacologic and nonpharmacologic therapies. The following medications, called mood stabilizers, are used to treat bipolar disorder and are also commonly used to treat seizures: Lithium (Eskalith) Valproic acid (Depakote) Carbamazepine (Carbatrol, Tegretol) Lamotrigine (Lamictal) Oxcarbazepine (Trileptal) Topiramate (Topamax) Levetiracetam (Keppra) Schizophrenia is a psychiatric disorder characterized by false beliefs, confused thinking, hallucinations, and reduced social engagement. It affects men and women equally. The exact causes of schizophrenia are unknown, but it's believed to be associated with abnormal levels of the neurotransmitter dopamine. Patients may suffer "positive symptoms" of delusion and hallucinations or "negative symptoms" such as social withdrawal, lack of interest, and reduced expression. It's a chronic, debilitating disorder that's very difficult to manage and requires a lot of emotional support from patients' family and friends. The following medications are commonly used to treat schizophrenia: Haloperidol (Haldol) Fluphenazine (Prolixin) Clozapine (Clozaril) Olanzapine (Zyprexa) Quetiapine (Seroquel) Risperidone (Risperdal) Aripiprazole (Abilify) Attention deficit hyperactivity disorder (ADHD) is more common in children younger than seven to eight years old. It's a neurobehavioral developmental disorder that involves lack of attention and increased hyperactivity. Three main behavioral symptoms include the inability to pay attention, impulsivity, and hyperactivity. Neurotransmitters that are believed to play an important role in ADHD are dopamine and norepinephrine.  The following medications, or central nervous system stimulants, are commonly used to treat ADHD: Amphetamine salt combo (Adderall) Dexmethylphenidate (Focalin) Dextroamphetamine (Dexedrine) Methylphenidate (Ritalin) Insomnia is a medical term used to describe the behavioral disorder of difficulty falling asleep, inability to stay asleep, and restlessness. Insomnia affects approximately 30–40 percent of the United States population. Various diseases and medications can cause varying degrees of insomnia. It's important to develop a routine before going to bed to help relax the body and avoid sleep disturbances. The following medications are used to treat insomnia: Zolpidem (Ambien) Eszopiclone (Lunesta) Zaleplon (Sonata) Trazodone (Desyrel) Amitriptyline (Elavil) Quetiapine (Seroquel)   Key Points Nervous system disorders may be caused by functional impairments, brain tissue degeneration, vascular abnormalities, trauma, or infections. Parkinson's disease is a slowly degenerative disease caused by shrinking levels of the neurotransmitter dopamine. Causes of Parkinson's disease are unknown, and there's no cure. Panic disorders and OCD are types of anxiety. All antidepressants increase the risk of suicide, so close monitoring and supervision of patients during initial treatment of antidepressants is imperative.               

Lesson 3 Overview In this lesson, you'll learn the basic components, functions, and diseases of the immune system. The immune system is comprised of white blood cells, enzymes, hormones, skin, bone marrow, and the lymphatic system. The immune system is your body’s defense mechanism to protect itself against various infections that can be caused by pathogens such as bacteria and viruses.  In addition, you'll learn in detail about the development and presentation of the most debilitating diseases—HIV infection and cancer. HIV is a virus that can destroy the immune system and expose your body to various infections. Cancer is a disease of uncontrolled cell division and growth that can spread to your entire body, taking over the normal bodily functions. You'll gain knowledge of various treatment options for immune system disorders, HIV infection, and cancer. While discussing treatment for these diseases, you will learn about the medications used to treat each disease. Medications are listed throughout this unit by their generic names, with brand names provided in parenthesis.   Lesson Objectives Illustrate immune system components and functions Describe the common immune system diseases and treatments Explain cancer and chemotherapy medications used to treat cancer   Introduction The immune system is your body's defensive network against any disease-causing microorganisms. It's a complex system composed of various organs, cells, enzymes, and hormones that provide protection against infection-causing microorganisms. Your body has two levels of protection against bacteria, viruses, parasites, and cancer. The integumentary system and certain types of blood cells are part of the first line of defense. Hair and the fluids lining the mucous membranes of the body openings provide physical and chemical barriers against pathogen invasion. Apart from producing an immediate immune response against pathogens, your body has a complex mechanism to produce antibodies against particular pathogens that are successful in invading the physical barrier. These antibodies then protect against future invasion of the same pathogen by initiating a full-blown immune response at the first trigger.    Functions of the Immune System The main function of the immune system is to prevent or decrease the risk of various infections. Individuals with weaker immune systems due to hereditary factors or concomitant diseases such as cancer and human immunodeficiency virus (HIV) infection are at higher risk of contracting life-threatening bacterial, viral, fungal, and parasitic infections. Microorganisms that a normal body is able to fight off easily can overtake patients with compromised immune systems.  Pregnant women have weaker immune systems as a protecting measure against the developing baby in the womb. The body may recognize new cells of the baby as foreign and may initiate an immune-mediated response to reject the pregnancy. Decreased effectiveness of the immune system in pregnant women is crucial, but puts women at risk of infections.  The immune system has a mechanism that differentiates between normal, healthy cells and unhealthy cells. The unhealthy cells may have been invaded by foreign microorganisms such as viruses, bacteria, and fungi, or they may have been damaged by noninfectious conditions such as sunburn and cancer. When the immune system first recognizes specific signals from these unhealthy cells, it immediately activates immune processes to attack these cells. If your immune system is unable to recognize and get activated when there's an invasion of pathogens, serious infections may occur. However, if the immune system gets activated without the invasion of disease-causing organisms, allergic reactions and autoimmune diseases occur. *The immune system is made up of a complex network of numerous cell types that either circulate throughout the body or reside in a particular tissue. Each cell type plays an important role in recognizing pathogens, communicating the message of danger to other cells, and working together to destroy the disease-causing pathogens.    Types of Immunity Innate immunity is the general and nonspecific immunity that your body possesses to fight various diseases. It comprises defense barriers such as the skin, hair, sebum, saliva, neutrophils, monocytes, and other enzymes that immediately detect and destroy the pathogens. It's a rapid-response system that acts as the first line of defense against infections. You're born with the components of innate immunity, and it can't be learned, created, or produced—hence the name "innate." Since bacteria and viruses multiply quickly, innate immunity is crucial in providing protection until the second line of defense, or adaptive immunity, starts involving in the process. In addition to providing the first line of defense against disease-causing microorganisms, the innate immune system activates, directs, and instructs components of the adaptive immunity. It also regulates inflammation and maintains equilibrium among various immune system processes.  Adaptive immunity, also referred to as acquired immunity, comes into play when innate immunity is breached. Adaptive immunity isn't very helpful in protecting your body when a specific bacteria, virus, or any other microorganism enters your body for the first time. Its components function by learning the pathogen and then developing immunity against it.    The adaptive immune system develops antibodies against the invading pathogen after the first entry. If the same or similar pathogen enters the bloodstream again, your body will have a defense ready to destroy the pathogen. The mechanism of adaptive immunity is essentially concerned with your body's capability to recognize and destroy substances which it interprets as foreign and harmful and is more complex than the innate immunity. Adaptive immune responses are continually refined and adjusted throughout your lifetime. As microorganism or your body's own defective cells trigger an immune response, the adaptive immune system continues to develop antibodies against these cells. The foreign substance is recognized by your body in the form of an outside protein called an antigen.  An antigen triggers the production of antibodies, which attack the antigen to destroy it. A specific type of white blood cell (WBC) called the lymphocyte is a major cell of the adaptive immune system. Lymphocytes are further classified as T lymphocytes (T cells) and B lymphocytes (B cells). Vaccines are manufactured based on the adaptive immune system function. An antigen derived from a particular disease-causing bacteria or virus is manufactured, then introduced into the body in the form of a vaccine. Vaccines are administered to healthy individuals to trigger the adaptive immune response and produce antibodies against the antigen without causing the disease.   Components of the Immune System Unlike the digestive, respiratory, and musculoskeletal systems, the immune system isn't an organized system of organs working together. It's essentially a functional system that depends on various cells, enzymes, hormones, skin, bone marrow, and the lymphatic system. Immune cells are produced in the bone marrow and are circulated to organs, where they mature and develop to become a part of the body's defense system. The lymphatic system helps to carry, circulate, and store the immune cells.  Many enzymes, proteins, and hormones released by various cells and glands also play a crucial role in the immune system's ability to carry out its functions of fighting infections.   The bone marrow produces white blood cells (WBCs), which play a major role in your body's defense mechanism on a cellular level. These cells are also known as leukocytes (leuko- means white and -cyte means cell). The main function of WBCs is to defend against infection and foreign invaders. An increase in the number of WBCs usually indicates infection. The bone marrow is the precursor to innate immune cells. It produces granulocytes, which are WBCs that contain secretory granules in their cytoplasm. There are three types of granulocytes: neutrophils, eosinophils, and basophils.  Neutrophils are the most prevalent type of WBCs. They respond to bacterial infections, such as pneumonia or urinary tract infections, by engulfing the bacteria through the process of phagocytosis and are often referred as phagocytes. If the infection is moderate or severe, the bone marrow will produce extra neutrophils. Neutrophils are observed during the early stages of acute inflammation.  Eosinophils are predominantly involved in allergic reactions. Their concentration may be elevated after allergic reactions to foods or drugs. Eosinophils also help fight parasitic infections.  Basophils, like the other granulocytes, are involved in the process of inflammation. They're the rarest of leucocytes.  Basophils help combat allergic reactions by releasing two chemicals: 1. Histamine 2. Heparin   The bone marrow, which is the precursor to innate immune cells, also produces agranulocytes, which are WBCs that don't contain secretory granules in their cytoplasm. There are two types of agranulocytes: 1. Lymphocytes 2. Monocytes - They're part of innate immunity and are the important first responders to infection. The bloodstream helps by continuously circulating immune cells throughout the body. Lymphocytes produce antibodies against foreign particles, such as microorganisms, drugs, cancerous cells, and cells from transplanted organs. Lymphocytes are further classified as T lymphocytes (T cells) and B lymphocytes ( B cells). B cells produce antibodies and T cells participate in cell-mediated immune responses against bacterial and viral infections. Lymphocytes primarily function as part of adaptive immunity by producing antibodies against the invader cells. If the same type of cell attacks again, your body's defense force, in the form of antibodies, is ready to attack. Monocytes, like neutrophils, are phagocytic cells, and their main function is to engulf and digest the damaged cells and pathogens. Monocytes function as part of innate immunity.    Antibodies, or immunoglobulins, bind with pathogens to deactivate them or tag them to be destroyed by specific WBCs. Producing antibodies against a known antigen is your body's way of providing future protection from infection by the same pathogen. Cytokines are proteins produced by various cells, including the immune cells. Cytokines play an important role in the immune system by sending and receiving signals to carry out various immune system processes. Cytokines communicate with immune cells to help regulate, direct, and amplify the immune response.  The thymus is a small endocrine gland located in the upper chest area. The main function of the thymus gland is to develop a newborn's immune response; in adults, the thymus continues to be important in the maturation of lymphocytes, specifically T lymphocytes. While the bone marrow is responsible for the production of lymphocytes from stem cells, only B cells mature there. T cells, on the other hand, mature in the thymus. First, the bone marrow sends some immature lymphocytes out to the blood to be deposited in the thymus gland. Here, the immature lymphocytes become thymocytes and further mature to become T lymphocytes or the T cells. T cells are responsible for the cell-mediated immunity. T cells don't produce antibodies. They simply attack atypical or abnormal cells, causing death of the diseased cell by activating microphages or by inducing a series of chemical reactions that encourage the cell to die (a process known as apoptosis). The thymus gland is considered a part of the lymphatic system. The lymphatic system is a network of vessels and tissues that carry lymph throughout your body. This system is also composed of the thymus gland and lymph nodes. Similar to blood, lymph is an extracellular fluid that continuously circulates throughout your body. Immune cells are carried through the lymphatic system and stored in lymph nodes, which are found throughout your body. The network of lymphatic capillaries, vessels, ducts, glands, and nodes perform a number of important jobs. This network transports excess fluid from the tissues back to the circulatory system, filters bacteria, acts as an emergency reservoir of blood, destroys and removes old red blood cells, and produces monocytes and T lymphocytes for the immune system. The lymphatic system also absorbs fats from the small intestine and delivers them into the bloodstream. Lymph nodes serve as spots where stored immune cells may detect a foreign pathogen and initiate the immune response against the pathogen. Thus, swollen lymph nodes are usually indicative of your body's active immune response. The spleen is a soft, dark red organ located on the left side of the abdomen, just below the diaphragm. Even though the spleen isn't directly connected to the lymphatic system, it plays an important part in your body's immune response. The spleen also stores immune cells and activates these cells to respond to disease-causing pathogens. It stores lymphocytes and other blood cells, and it filters out bacteria and viruses from the arterial blood circulation. As the blood passes through the capillary network in the spleen, it comes into contact with lymphocytes that clear the blood of any infected cells that may be there. T cells, as you've learned, work to destroy atypical, infected, or defective cells. B cells produce antibodies that will work to destroy future infections when they're recognized again. In a fetus, one of the main functions of the spleen is to produce lymphocytes and red blood cells. Before the long bones are fully formed and able to produce cells, the spleen is where blood cell formation occurs. Once the bones take over production, the spleen focuses on storing and filtering blood and fighting infection. The tonsils are masses of lymph tissue located in the rear of the throat. Their location as "guards" of the mouth often exposes them to microorganism invading the body through food and air. Like all lymphoid tissue, they store lymphocytes and release them to fight infections as soon as microorganisms enter the mouth.    Key Points The immune system is your body's defense against foreign pathogens; it prevents or decreases the risk of various infections. Your body produces two types of immune response, innate and adaptive. Innate immunity is general and nonspecific immunity against any pathogen or allergen trying to enter your body. Adaptive immunity is specific and learned immunity against a specific pathogen or allergen. Major components of the immune system include skin, hair, mucus, blood, WBCs, bone marrow, antibodies, cytokines, enzymes, and the lymphatic system. The lymphatic system includes a network of vessels, the thymus gland, spleen, lymph nodes, and tonsils.                    

Introduction The immune system mainly serves to protect your body from various infections. Its components achieve this goal by being specific for each pathogen, by being mobile to reach all body organs, and by memorizing the antigen to provide future protection. Immune cells possess the ability to replicate themselves to amplify the immune response. Without a healthy immune system, your body is exposed to many pathogens capable of causing severe and fatal infections. Weak or comprised immune systems drastically increase the risk of infections. However, hyperactive or prolonged immune response causes hypersensitivity or allergic reactions. Allergic reactions may be caused by a disease-causing allergen or by any otherwise normal environmental component. Your body can initiate an immune response against your own body cells or tissues, resulting in autoimmune diseases.    Diseases of the Immune System Diseases such as myasthenia gravis (MG), rheumatoid arthritis (RA), insulin-dependent diabetes mellitus (IDDM), multiple sclerosis (MS), and Lupus (SLE) are known to be caused by the body's autoimmune response. Autoimmune diseases can be treated using immunosuppressive medications such as cyclosporine, azathioprine, and mycophenolate. Immunodeficiency is another disease related to the immune system.  Acquired immune deficiency syndrome (AIDS), caused by human immunodeficiency virus (HIV), is one of the most serious immunodeficiency diseases. HIV is a virus that causes AIDS, a disease that suppresses the body's natural immune system. The virus destroys T lymphocytes (T cells) that fight infections, leaving patients prone to deadly infections. In some cases, the immune system is suppressed using medications to protect against autoimmune diseases and certain cancers. It's also sometimes done to prevent organ rejection after an organ transplant.  When HIV infection first began spreading in the United States, it was thought to be an exclusive disease among the homosexual male population. Soon thereafter, it became evident that HIV infection was being passed not only between homosexual males, but also through blood transfusions, intravenous drug use, male-to-female sexual contact, female-to-female sexual contact, mother to baby, and exposure in the workplace from patient to healthcare worker.   Human Immunodeficiency Virus (HIV) Infection HIV is most commonly found in blood, semen, and vaginal secretions. The greatest risk factors for contracting HIV infection are participating in unprotected sexual activity and intravenous drug abuse where a needle is shared with an HIV-positive person. The virus can be passed along from the mother to the fetus or from the mother to the infant during delivery. Before 1985, transmission occurred through transfusion of HIV-contaminated blood products, but this form of transmission has virtually stopped due to blood screenings.  It's important to note that a person can be infected with HIV for years before developing AIDS. During this time, the infected person can unknowingly transmit the virus to others. AIDS is a fatal disease because it's impossible to cure. HIV infection suppresses the immune system so that it can no longer fight diseases and infections, eventually leading to death. There are treatments available now that may prevent the virus from actually developing into AIDS. Even though these HIV medications may not cure AIDS, they're helping patients to live longer. During the early stage of HIV infection, the patient experiences mild symptoms such as fever, diarrhea, sore throat, and muscle aches. The ability to fend off diseases remains quite good.  A mid-stage period of HIV infection is persistent generalized lymphadenopathy, in which enlarged lymph nodes, skin rashes, chronic fatigue, and weight loss occur. Finally, full-blown AIDS strikes, rendering the immune system powerless. The patient becomes subject to opportunistic infections such as Kaposi's sarcoma (KS), Pneumocystis carinii pneumonia (PCP), and lymphoma.  * Viruses are tricky microorganisms that are constantly changing and reproducing, so new research is always needed for prevention and treatment.   The HIV life cycle starts once HIV enters the host blood, where it attacks a specific type of T cells called CD4 cells. HIV binds to the chemokine receptor 5 (CCR5) on the CD4 cell surface. HIV then fuses with the CD4 surface to inject its ribonucleic acid (RNA) into the cell along with other viral proteins necessary for the virus to replicate. The CCR5 receptor is the target of new research on HIV treatment. Fusion inhibitors are also one of the newer class of HIV medications that target the enzyme that helps in fusing HIV to the CD4 cell surface.  Once inside the CD4 cell, viral RNA is converted into viral deoxyribonucleic acid (DNA) with the help of an enzyme called reverse transcriptase. Many HIV medications, called reverse transcriptase inhibitors, target this enzyme to stop the replication process. Viral DNA then crosses into the cell nucleus and inserts itself into the host DNA with the help of an enzyme called integrase. Another class of HIV medications, called integrase inhibitors, targets this enzyme to halt the virus replication.    Once the viral DNA is incorporated into the host DNA, it starts replicating to produce multiple strands of the new viral RNA. New viral RNA synthesizes its own viral proteins and an immature HIV develops. An enzyme called protease helps in the maturation process of the immature virus. Protease inhibitors are another class of HIV medications, which target HIV replications at this last step of virus multiplication.  Once HIV takes over the host CD4 cells, it starts replicating to manufacture enough HIV to cause infection and symptoms of the disease. As the number of functional CD4 cells decreases, the body's immune system capability starts decreasing as well. The decrease in the body's functional immune response increases its risk of contracting infections, leading to complications of the disease and, eventually, death if treatment is unable to control the virus multiplication.   The following provides a summary of HIV replication: 1. Binding—HIV binds to the CD4 cell surface. 2. Fusion—HIV and CD4 cell membrane fuse. 3. Reverse transcription—HIV, using its enzyme reverse transcriptase, converts its RNA into DNA. DNA then enters the CD4 cell nucleus. 4. Integration—Another HIV enzyme, integrase, facilitates the insertion of the HIV DNA into the CD4 cell DNA. 5. Replication—Now as part of the CD4 DNA, HIV begins to replicate its own RNA and other HIV proteins. 6. Assembly—New HIV RNA, along with other viral proteins, produces an immature HIV. 7. Budding—Immature HIV comes out of the CD4 cell and uses its own enzyme called protease to become a mature and infectious HIV.   There are many HIV medications on the market and many more on the horizon. Reverse transcriptase, protease, and integrase have been the target f HIV research for years, and many medications are available that target these enzymes to control the replication of HIV and progression of AIDS. Fusion inhibitors and CCR5 antagonists are the newer targets for the HIV treatment.  HIV medications are never used as a single drug therapy. HIV is targeted with a combination of 2- ,3- , or even a 4-drug regimen. HIV is a notorious virus that changes its genomic structure rapidly and may develop resistance to the HIV drugs quickly. Combination regimens decrease the risk of resistance to HIV drugs and increases treatment efficacy. It's important for patients to adhere strictly to the prescribed regimen to reduce the risk of resistance and increase the effectiveness of these drugs.   HIV drugs that are currently available on the market are listed in the following HIV Medications table. Reverse transcriptase inhibitors are further divided into two classes—nucleoside reverse transcriptase inhibitors (NRTIs) and non-nucleoside reverse transcriptase inhibitors (NNRTIs)—based on their structure and mechanism of inhibiting the enzyme. Since generic names of HIV medications are long and complex, these medications are commonly referred to by the acronyms given in parentheses next to the generic name, as shown in the HIV Medications tables.              Drug Class: Nucleoside Reverse Transcriptase Inhibitors (NRTIs)   Mechanism of Action Exert effect on step 3 of the HIV replication by inhibiting the enzyme reverse transcriptase. Generic Name                           Brand Name Abacavir (ABC)                             Ziagen Didanosine (ddl)                          Videx Emtricitabine                               Emtriva Lamivudine (3TC)                        Epivir Stavudine (d4T)                           Zerit Tenofovir (TDF)                           Viread Zidovudine (AZT)                        Retrovir   Drug Class: Non-Nucleoside Reverse Transcriptase Inhibitors (NNRTIs)   Mechanism of Action Exert effect on step 3 of the HIV replication by inhibiting the enzyme reverse transcriptase. Generic Name                   Brand Name Delavirdine (DLV)                Rescriptor Efavirenz (EFV)                     Sustiva Etravirine (ETR)                   Intelence Nevirapine (NVP)                Viramune     Drug Class: Protease Inhibitors (PIs)   Mechanism of Action Exert effect on step 7 of the HIV replication by inhibiting the enzyme protease. Generic Name Atazanavir (ATV) Darunavir (DRV) Fosamprenavir (FPV) Indinavir (IDV) Lopinavir/Ritonavir (LPVr) Nelfinavir (NFV) Ritonavir (RTV) Saquinavir (SQV) Brand Name Reyataz Prezista Lexiva Crixivan Kaletra Viracept Norvir Invirase   Drug Class: Fusion Inhibitor   Mechanism of Action Exerts effect on step 2 of the HIV replication. Generic Name Enfuvirtide (T20) Brand Name Fuzeon   Drug Class: CCR5 Antagonist   Mechanism of Action Exerts effect on step 1 of the HIV replication. Generic Name Maraviroc  Brand Name Selzentry   Drug Class: Integrase Inhibitor   Mechanism of Action Exerts effect on step 4 of the HIV replication by inhibiting the enzyme integrase. Generic Name Raltegravir (RAL) Brand Name Isentress   Drug Class: Combination Products   Mechanism of Action Common commercially available combination products of 2 or more medications. Generic Name Zidovudine + Lamivudine Efavirenz + Emtricitabine + Tenofovir Abacavir + Lamivudine + Zidovudine Brand Name Combivir Atripla Trizivir     Highly Active Antiretroviral Therapy (HAART) is a term that refers to the combination of antivirals used to effectively treat HIV infection. Combination regimens of different classes of medication that are proven to be safe and effective are called HAART regimens. HAART regimens improve efficacy as well as reduce HIV resistance.    HIV patients or patients with weaker immune systems are at high risk of serious infections such as opportunistic infections, pneumocystis jirovecii pneumonia (PJP), and mycobacterium avium complex (MAC). Pneumocystis jirovecii pneumonia (PJP) and mycobacterium avium complex (MAC) are the two common types of opportunistic infections in HIV-infected patients. Opportunistic infections are infections caused by microorganisms that are otherwise rarely infectious to individuals with good immune systems. HIV-infected patients or patients with weaker immune systems are at high risk of having opportunistic infections. These infections may be fatal for HIV-infected patients. PJP is a type of lung infection, or pneumonia, caused by a microorganism called Pneumocystis jirovecii. It's the most common and life-threatening infection in HIV-infected patients. PCP prophylaxis with the following medications is recommended for patients with HIV infection;  Sulfamethoxazole/Trimethoprim (Bactrim) Dapsone (Dapsone) Atovaquone (Mepron) Pentamidine inhalation (Nebupent)                                                        MAC is a group of bacteria that can cause serious and deadly infections of the lungs, bones, and blood in HIV patients. MAC infection is generally considered an end-stage complication of AIDS. MAC prophylaxis with the following medications is recommended for patients with HIV infection: Azithromycin (Zithromax) Clarithromycin (Biaxin) Rifabutin (Mycobutin)   Organ Transplant Rejection and Immunosuppression  There are three types of organ rejection based on the time elapse between the organ transplant and the rejection: hyperacute, acute, and chronic.  Hyperacute rejection occurs within minutes of implanting a new organ. One of the main causes of this type of rejection is mismatched blood type or other markers. Hyperacute rejection usually requires removal of the new organ. Acute rejection occurs within two or three weeks of the organ transplant. It's a T-cell mediated immune response to specific markers on the donor organ. Chronic rejection usually occurs after three or more months of the organ transplant. It's a B-cell mediated response that produces antibodies against the donor organ.   Immunosuppression is a phenomenon of decreased or total lack of immune response in the body. It may be caused by diseases such as cancer and HIV infection. Immunosuppression may also be induced during an organ transplant and then be continued as maintenance therapy to prevent chronic rejection. Patients on immunosuppressive medications after an organ transplant are at a higher risk of contracting infections. Patients are generally instructed to practice good hand hygiene, avoid close contact with the sick, and stay away from crowded places. To prevent acute organ rejection, induction immunosuppressive therapy is administered before, during, or immediately after the organ transplant. Induction therapy works by depleting functional lymphocytes to prevent an immediate immune response against the new organ. The following medications are commonly used as induction therapy to eliminate all antibodies against the new organ: Antithymocyte globulin (Atgam or ATG, and rATG) Muromonab-CD3 (OKT3) Anti-interleukin-2 (IL-2) Basiliximab (Simulect) Maintenance Immunosuppression Therapy Various combinations of immunosuppressive medications are used for continuous immunosuppression to prevent chronic rejection of the new organ. These medications work by suppressing, inhibiting, or decreasing the production of the T cells and B cells. The following medications are commonly used to avoid chronic rejection: Cyclosporine (Sandimmune, Neoral) Tacrolimus (Prograf) Methylprednisolone (Solu-Medrol) Prednisone (Prelone) Azathioprine (Imuran) Mycophenolate (CellCept)   Key Points The immune system may become weak due to diseases such as HIV infection. The immune system may become overactive or hyperactive due to an allergen, resulting in a hypersensitivity reaction. Examples include allergic reaction from a bee sting or taking medications such as sulfa drugs and penicillin. Sometimes the immune system stays hyperactive over periods of time due to normal environmental components causing allergies such as seasonal allergy to pollens or grass. Your own body cells and tissues can trigger an immune response, causing various autoimmune diseases such as myasthenia gravis, rheumatoid arthritis, and multiple sclerosis. HIV infection is the most notorious immune system disease and can expose your body to fatal infections. There are many HIV medications that can control the progression of the disease, but there's still no cure for AIDS.                                    

Introduction Cells in your body are constantly growing and dividing. Sometimes, cells begin to multiply in an uncontrolled fashion and develop an abnormal tissue or growth. The abnormal cells or growth have no useful physiological purpose in the body and can cause irreparable damage. These abnormal growths are called neoplasms. The study of neoplasms is called oncology. A neoplasm can be benign or malignant. Both types of neoplasm can cause a lump to form in the tissue, called a tumor. Tumor is a word that's used synonymously with neoplasm. A benign neoplasm is sometimes referred to as a benign tumor. A malignant neoplasm is called cancer. Cancer isn't always a solid tumor. Cancer can originate in body cells that are floating around, such as blood cells and lymph cells. These cells aren't fixed to a particular organ or body structure. Abnormalities in these floating cells are even more dangerous because cancer can spread to various body parts much quicker.    Causes of Cancer The following characteristics differentiate benign tumors from cancerous tumors: Benign tumors grow slowly; cancer grows rapidly. Benign tumors are often enclosed by a well-defined membrane border; cancerous tumors are non-encapsulated, with an ill-defined membrane border, and project into surrounding tissues. Benign tumors don't usually cause harm to the body unless they're large and interfere with the proper functioning of surrounding tissue. For example, due to the limited space in the cranium, benign brain tumors may be harmful to the surrounding brain tissue. Malignant neoplasms or cancer cells are always dangerous, no matter where they are, since the cells will travel through blood and lymph to invade tissues near and far. Benign neoplasms don't usually grow back after surgical removal; cancer cells frequently regenerate after surgical removal.   Normal cells can transform into cancerous cells through a process called carcinogenesis. Researchers believe this process occurs in the genetic code of the cells, the deoxyribonucleic acid (DNA) of chromosomes. In normal cell division, a group of genes called proto-oncogenes handle the proteins necessary for that division. In normal DNA, DNA repair genes and tumor suppressor genes can reverse damage in the cells. The DNA repair genes correct any abnormalities in cells before they divide. The tumor suppressor genes control the growth rate of cells, instructing them to kill themselves (apoptosis) if they start multiplying too rapidly or if the DNA repair genes can't fix the defect. If these protooncogenes mutate, they become known as oncogenes. Oncogenes instruct cells to make proteins that result in excessive cell growth and abnormal division. These oncogenes can convert normal cells to cancer cells. If the oncogene has affected the DNA repair genes and the tumor suppressor genes, the cells have no instructions to slow down. Thus, they continue to produce abnormalities in daughter cells faster and faster. Once the genetic material of a cell has transformed, or mutated, the correct genetic code is lost. During mitosis, or cell division, the oncogene parent cell will produce two new abnormal cells instead of healthy cells. The mutated cells grow quickly in number and form a tumor. A change in DNA structure can be passed down to subsequent generations through the transfer of DNA from parents to a fetus.   Some cancers result from a defect in the arrangement of DNA chromosomes in the original egg and sperm that created the individual. A child can be born with a defect in the chromosomes that will cause mutation if activated. The factors that activate a gene are unclear. Some cancers have biological causes, relating to factors such as aging and reproductive history. These changes happen during a person's lifetime. They're called acquired, or somatic, mutations. For instance, the risk of prostate cancer increases substantially in men over age 65. And women who never had children, or had their first child after age 30, are at higher risk of developing breast cancer. At least half of all cancers are believed to have direct environmental causes. Chemicals, drugs, viruses. and other agents called carcinogens can lead to changes in DNA, and thus to cancer. A major carcinogen is tobacco smoke, which accounts for 90 percent of all lung cancers.   The following carcinogens are commonly found in our working and living environments: Household chemicals: Benzene in glues, insecticides, tobacco smoke, and additives in processed foods Industrial pollutants: Arsenic from mining and smelting, asbestos from construction, benzene from oil refineries  Radiation: Ultraviolet rays from the sun, X-rays and radioactive substances from diagnostic and therapeutic procedures Hormones: Primarily the synthetic estrogen diethylstilbestrol (DES) Viruses: Hepatitis B virus can lead to liver cancer and human papillomavirus is known to cause cervical cancer.   Early Signs of Cancer Usually, the growth of malignant cells doesn't cause noticeable symptoms right away, but physicians who know what to look for can detect early signs of cancers. The American Cancer Society recommends regular physical exams and has publicized the acronym CAUTION, which states the following seven early danger signs of cancer: C Change in bowel habit  A A sore that doesn't heal U Unusual bleeding or discharge T Thickening of tissue or a lump I Indigestion or trouble swallowing O Obvious changes to moles or warts N Nagging cough or persistent hoarseness    Types of Cancer There are many known types of cancer. They're classified according to the type of tissue cells they grow. Classifications containing the suffix -oma, which means "tumor", connected to a body part word, are almost always benign. Examples include papilloma (an epithelial tumor), adenoma (a tumor originating in a gland), or osteoma (a bony tumor usually found on the skull). But the combining forms carcin(o) and sarc(o) turn the suffix -oma into a serious illness. Blood and lymph cancers typically originate in the bone marrow.  Carcinomas are cancers that originate in the epithelial tissues and include most breast, stomach, uterine, skin, tongue, and glandular cancers. Some examples are esophageal carcinoma, carcinoma of the breast, and squamous cell carcinoma of the skin. The great majority (about 90 percent) of cancers are carcinomas.  Sarcomas are cancers that originate in connective tissues such as bones, muscles, and lymph. They're often named by adding the suffix -sarcoma to the combining form for that tissue. Examples include osteosarcoma, cancer originating in bone tissue; chondrosarcoma, cancer originating in cartilage; and liposarcoma, cancer originating in fat tissue. Sarcomas are the minority form of cancer, but they're generally more fast-growing and deadly than carcinomas. Blood and lymph cancers usually originate in the bone marrow where blood and lymph cells are produced. Examples of these cancers include leukemia, non-Hodgkin's lymphoma, and multiple myeloma.    Grading and Staging When physicians classify malignant tumors, they may use a number of techniques. Two systems, grading and staging, are in widespread use to help physicians study cancer and establish consistent diagnosis and treatment procedures. Several grading and staging systems are available for specific types of neoplasms. There's also a general grading and staging system that may be used alone or in combination with a tumor-specific system to give healthcare providers the most detailed picture possible of the disease in question. Grading is the microscopic study of a tumor specimen to determine the degree of cell differentiation. The most common grading scale is the Broders's index, which has the following four classifications: Grade 1 means the tumor is highly differentiated, or close to normal parent tissue, but some abnormality is present. Grade 2 means the tumor is moderately differentiated, or not as close to normal parent tissue and the cells are fairly irregular. Grade 3 means the tumor is poorly differentiated, or quite far from normal parent tissue, and the tissue of origin may even be difficult to identify. Grade 4 means the tumor is dedifferentiated, or anaplastic, and so immature and primitive that it's virtually impossible to tell what is the parent tissue. Grade 1 indicates an early stage of abnormality, and Grade 4 indicates a full-blown malignancy. The prognosis is good for patients with Grade 1 tumors and worsens as the grades go up. *Cancer is sometimes classified as stage I through stage IV depending on how far the tumor cells have spread from the original site. Stage I is assigned when the tumor cells are localized at the original site only. As the tumor spreads further from the original site, the stage level increases to stage II and stage III. Stage IV is assigned when cancer is spread to many organs throughout the body. Stage 1 has the best chance of successful treatment, and treatment success declines as the stage number increases.   Cancer Treatment Cancer treatment depends on various factors, such as the type, the location, and the grading and staging of cancer. If cancer is in the form of a solid tumor and in its initial stage, it's likely that surgical removal followed by radiation treatment is sufficient to fully treat the patient. Radiation therapy is used post-surgery to target any remaining cancer cell fragments by exposing the cancer site to direct radiation treatments. Treating cancer with medication is known as chemotherapy. Chemotherapy is often combined with surgery and radiation to treat advanced stages of cancer. The goal of cancer chemotherapy is to introduce agents that will kill malignant tissue while leaving all the healthy tissue intact. The term chemotherapy regimen means there are two or more antitumor drugs being used to destroy the malignancy. If everything goes well, the patient will go into remission, meaning all signs of the disease will disappear. Antitumor drugs are referred to as antineoplastic agents, meaning they inhibit the maturation and reproduction of malignant cells. Different drugs are used, and in different combinations, depending on the type, stage, grade, and location of cancer as well as the patient's condition.   Alkylating agents kill rapidly proliferating malignant cells by preventing DNA replication. These medications work by attaching an "alkyl" group to the DNA or otherwise damaging the DNA. While fast dividing cancer cells are unable to detect this error, resulting in DNA damage and cancer cell death, healthy cells generally can correct this error. Nitrogen Mustard was one of the first alkylating agents used to treat cancer and was also one of the modern drugs to effectively treat cancer. One of the disadvantages of these drugs is their non-specificity to the cancer cells. Commonly used alkylating and alkylating-like agents are: Carboplatin (Paraplatin) Carmustine (BiCNU) Chlorambucil (Leukeran) Cisplatin (Platinol) Cyclophosphamide (Cytoxan) Mechlorethamine hydrochloride (Mustargen) Oxaliplatin (Eloxatin) Temozolomide (Temodar) Antimetabolites are a class of medications commonly used to treat various cancers. These medications inhibit certain metabolites that are essential to carry out cell metabolism, causing defects in cell growth and multiplication. Since cancer cells divide and grow exponentially, these medications act more quickly on growing cancer cells than on normal, healthy cells. Just like any other chemotherapy medication, there's some damage to healthy cells along with cancer cells. To avoid damage to healthy cells, chemotherapy regimens are often given in cycles of every three to six weeks. The time between the chemotherapy regimens allow the body to recover from the side effects. Commonly used antimetabolites are: Azathioprine (Imuran) Cytarabine (Cytosar-U) Fludarabine (Fludara) Fluorouracil (5-FU) Mercaptopurine (Purinethol) Methotrexate (Trexall) Antitumor antibiotics aren't the same as antibiotics. These agents prevent the normal replication of nucleic acids (DNA and RNA). These medications work by binding to the DNA to halt the RNA synthesis, in turn causing cancer cell death. The antitumor antibiotics commonly used are: Bleomycin (Blenoxane) Dactinomycin (Cosmegen) Daunorubicin (Cerubidine) Doxorubicin (Adriamycin) Epirubicin (Ellence) Idarubicin (Idamycin) Mitomycin (Mutamycin) Mitoxantrone (Novantrone) Vinca alkaloids, also called plant alkaloids, are drugs derived from plants. They inhibit cell division at a specific step during the cell cycle. The vinca alkaloids commonly used are: Vinblastine (Velban) Vincristine (Vincasar) Vinorelbine (Navelbine) Hormones are essential for conducting many key processes and reactions in your body. Unfortunately, hormones may at times trigger or aid in the development of certain cancers such as breast cancer, prostate cancer, and other cancers of the reproductive organs. Antihormones (agents that counteract hormones) and certain steroid analogs of hormones are commonly used to treat these types of cancers. Hormone analogs compete to bind to the hormone receptor sites to stop or reduce cancer cell growth. These agents are successfully used to treat various hormone-dependent cancers, such as estrogen-dependent breast cancer. The hormone-like agents commonly used are: Anastrozole (Arimidex) Bicalutamide (Casodex) Exemestane (Aromasin) Letrozole (Femara) Tamoxifen (Soltamox) Toremifene (Fareston) Immunomodulating drugs work by activating the immune system or modifying a biological response to an unwanted stimulus such as a tumor. These drugs either boost your body's immune system so that it's more active in destroying cancer cells, or they make the cancer cells more evident to the immune system. They may also enhance your body's ability to recover from other therapies, such as radiation and chemotherapy. Monoclonal antibodies are used successfully as immune system modulators to treat many types of cancers. These antibodies are produced in the laboratory. Scientists use the tumor material itself to determine which antigens are present on the neoplasm, identify which antibodies work against that particular antigen, and then replicate these antibodies. They can then inject the antibodies directly toward the tumor. They can even attach radiological or chemotherapeutic materials to the antibodies that will enhance the disease-fighting ability of the antibodies themselves. This therapy has been successful in treating leukemia and lymphoma. The monoclonal antibodies commonly used are: Bevacizumab (Avastin) Cetuximab (Erbitux) Rituximab (Rituxan) Trastuzumab (Herceptin) Siltuximab (Sylvant) Interferons are natural proteins produced by cells in reaction to viruses or bacteria. Interferons inhibit viral strains from reproducing, trigger microphages to engulf or eat cancer cells, and increase antigens so lymphocytes can produce antibodies against them. Interferons are used in the treatment of malignant melanoma (a type of skin cancer), some types of leukemia, non-Hodgkin's lymphoma, and AIDS-related Kaposi's sarcoma. The interferon drugs commonly used are: Interferon Alfa-2b (Intron A) Peginterferon Beta-1a (Plegridy)   Side Effects of Chemotherapy Antineoplastic therapy is a dangerous undertaking. The drugs are strong enough to kill cancer cells, and also likely to kill rapidly proliferating healthy tissue, especially in the GI tract, the scalp, and the bone marrow. Common side effects of chemotherapy medications include hair loss, pain, fatigue, nausea, vomiting, diarrhea, stomatitis, and reduced blood cell production.  Patients are susceptible to infection because of a weakened immune system. Patients undergoing chemotherapy are often weak and require many medications pre- and post-chemotherapy to manage the serious side effects of chemotherapy. Nausea and vomiting induced by chemotherapy medications are notorious. The best management for nausea and vomiting is to give the appropriate medications prior to the initiation of chemotherapy and continue for three to five days after completion of the chemotherapy regimen. Once patients start feeling the symptoms of nausea, it's very difficult to treat with even the strongest anti-nausea medications. It's very important to instruct patients to continue taking prescribed nausea medications for prevention. Chemotherapy-Induced Nausea and Vomiting Medications The following medications are commonly used to treat chemotherapy-induced nausea and vomiting: Dexamethasone (Decadron) Granisetron (Kytril) Lorazepam (Ativan) Ondansetron (Zofran) Prochlorperazine (Compazine) Stomatitis is an inflamed and sore mouth. There are different types of stomatitis. It's caused by irritated mucous membranes in the mouth. Chemotherapy medications often kill rapidly dividing cells of the mucous membrane in your mouth, leading to irritation and swelling. Patients are often prescribed topical anesthetics such as Lidocaine (Xylocaine) to apply locally for the numbness effect.  Leukopenia is defined as a reduction in the number of leukocytes in the blood. Patients with a decreased level of leukocytes or WBCs are at a higher risk to catch infections because WBCs are the primary cells that protect the body against infections. Medications on the market called granulocyte-stimulating factors help increase the production and maturation of leukocytes. The following two medications are commonly used to boost the levels of WBCs after chemotherapy: 1. Filgrastim (Neupogen) 2. Pegfilgrastim (Neulasta) Pain. Patients often need pain medications to control aches and pains due to chemotherapy. The following pain medications are commonly used: Acetaminophen (Tylenol) Ibuprofen (Motrin) Hydrocodone/acetaminophen (Vicodin) Acetaminophen/codeine (Tylenol #3) Oxycodone (OxyContin) Morphine Sulfate (MS Contin) Fatigue. Since chemotherapy medications also effect normal cells in the body, it's common for patients to feel very tired while on chemotherapy medications. A well-balanced diet and rest are important to keep the body energized to cope with the disease. Alopecia is defined as hair loss. Patients often have to wear wigs or scarves to cover their scalp. Hair grows back once chemotherapy treatment is completed.    Key Points Cells have highly regulated and highly controlled ways of directing and maintaining body processes, so when anything goes wrong in these highly controlled processes, cells start to divide, grow, and multiply erratically. This uncontrolled growth leads to the formation of tumors. When tumors are normal healthy cells in abundance, this is called a benign tumor. Benign tumors are much less dangerous than cancerous tumors because these tumors remain localized. When a tumor is made up of deformed cells, it's called a malignant or cancerous tumor. Cancer is highly treatable during initial stages with the use of chemotherapy, surgery, and radiation, but once a cancer has metastasized from its original site to the other parts of the body, it becomes difficult to treat and patients have a poor prognosis.  Cancers can be solid tumors but could also be in the cells and fluids that circulate throughout your body. Examples of this are blood cancer and lymphoma (cancer of the lymph cells).