Anatomy - Chapters 7&8

Chapter 7: Skeletal System Major Bone Functions SUPPORT by giving shape to head, face, limbs, etc. and supporting weight in lower limbsPROTECT the eyes and brain through skull, heart and lungs through ribsAID MOVEMENT through attachment to muscles and making a bone/muscle leverHEMATOPOIESIS which is the production of blood cells in red marrowINORGANIC SALT STORAGE for mainly calcium, which is important in most metabolic processes Structure of the Long Bone Diaphysis - middle shaft covered in tough tissue called periosteum made of compact bone (no air spaces) the center is called the medullary cavity filled with yellow marrow Epiphysis - the ends of the bone covered in cartilage made of spongy bone (air spaces) filled with red marrow

Structure of Microscopic Bone The bone as a whole is made of concentric circles of a calcium carbonate and calcium phosphate matrix, with a central canal on the inside (where the blood vessels and nerves are).OSTEOCYTES Found: small spaces in the circles in the bone called the lacunaFunction: transmits signals like the nervous system and modification/repair of bone Bone Development INTRAMEMBRANOUS BONES- broad, flat bones from fetal connective tissue form the template for development- osteoblasts secrete a matrix on it to form the boneENDOCHONDRAL BONES- cartilage template is made, but then primary ossification starting in the diaphysis- secondary ossification then starts in the epiphysis until bone is "rigid"- these bones can grow (during stages of life) because of an epiphyseal plate in them- as soon as the plate ossifies, growth is finished Skeleton Organization AXIAL SKELETON is made up of bones in the trunk or center of your bodyAPPENDICULAR SKELETON is made up of limbs or attachments

Other Important Bones THE SKULL made of the hyoid, cranial bones (8), and facial bones (14) baby's skull has fontanels, which are membranous portions (or soft spots) so they can be birthed easier but eventually close contains large orbits for eyes, a pronounced forehead and small face THE VERTEBRAL COLUMN made of 3 division of vertebrae (cervical, thoracic and lumbar) the sacrum is made of fused vertebrae in the pelvis the coccyx is a small tailbox at the end of the sacrum THE THORACIC CAGE protects the heart and lungs 12 pairs of ribs, but the first 7 are TRUE ribs and last 5 are FALSE ribs THE PECTORAL GIRDLE made of the scapula and clavicle connects upper limbs to the skeleton, and aids movement THE PELVIC GRIDLE the girdle is made of 2 hipbones (the coxae) if you add the sacrum and coccyx, the pelvis is formed UPPER LIMBS humerus, radius, ulna in upper arm hand made of 8 carpals, 5 metacarpals, and 14 phalanges LOWER LIMBS femur, tibia, fibula with patella bone in upper leg ankle/foot made of 7 tarsals, 5 metatarsals, and 14 phalanges Chapter 8: Muscular System Smooth Muscle found in the stomach wall and esophagus, etc. unstriated involuntary 1 nucleus per cell Cardiac Muscle found in the heart striated involuntary 1 nucleus per cell Diseases Affecting Muscles MUSCULAR DYSTROPHY is when proteins are missing, causing weakened muscles that degenerate over time. Duchenne's muscular dystrophy only affects boys, who will die in early adulthood.CHARCOT-MARIE-TOOTH DISEASE is caused by a duplicate gene that impairs myelin formation, that causes a slow progression of symptoms that resemble AIDS, diabetes and vitamin deficiency.MYOTONIC DYSTROPHY delays muscle relaxation following a contraction, which can cause irregular heartbeats or facial muscle weakness. It gets inherited genetically and worsens with subsequent generations.HEREDITARY IDIOPATHIC DILATED CARDIOMYOPATHY is a very rare form of heart failure caused by the inability of action to anchor to Z lines in heart muscles, the chambers of the heart enlarge and not function leading to a 50% lethality rate. Steps of a Muscle Contraction 1. RELEASE OF ACETYLCHOLINEThe neurotransmitter of acetylcholine moves down nerve impulses to bind to the motor plate.2. MUSCLE IMPULSEThe impulse is stimulated and spreads into muscle tubules.3. MOVEMENTCisternae become more permeable and want to take calcium, meanwhile calcium moves out of the sarcoplasmic reticulum TO THE SARCOPLASM.4. EXPOSING AND BINDINGHigh calcium in sarcoplasm causes the actin to want to bind to TROPONIN and TROPOMYOSIN.5. CONTRACTIONThe myosin heads pull on the actin, and the ATP fuels the myosin meaning the contraction lasts as long as acetylcholine is present.6. RELAXATIONAcetylcholine is broken down, and the calcium goes back into the sarcoplasmic reticulum.

Neuromuscular Junctions and Neurotransmitters A MOTOR NEURON is a nerve that connects to a muscle fiber, and a NEUROMUSCULAR JUNCTION is the connection between nerve and muscle fiber. The MOTOR END PLATE is the specialized area of the sarcolemma modified to connect with nerve, meanwhile the messengers sent that are stored in the synaptic vesicles are NEUROTRANSMITTERS. Structure of a Myofibril Generally, just compose of myosin and actin filaments, and when these filaments overlap, they create striations.Z-LINE is the attachment for actinM-LINE is the attachment for myosinI-BAND is a zone of ONLY actin filamentsA-BAND is a zone that contains myosinH-ZONE is a zone containing ONLY myosin filamentsSARCOMERE is a single unit measured from one Z-line to the next Oxygen An oxygen debt occurs is the amount of oxygen needed for the liver to convert lactic acid and how much is needed by the muscle to reset the other sources.