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| Questão | Responda |
| What are some characteristics of the Nervous System? | - Works using neurons to send action potentials which secrete a neurotransmitter to a postsynaptic membrane - Briefer response - Shorter effect |
| What are the target cells for the Nervous System? | - Muscle cells - Gland cells - Other neurons |
| What are some characteristics of the Endocrine System? | - Controls functions of the body using hormones - Hormones are at 1 part of the body but regulates the activity of another part of the body - Longer time to respond - Longer effect |
| What are the target cells for the Endocrine System? | Every target cell in the body |
| How do hormones travel? | Through the bloodstream |
| What are the 2 types of Glands? | - Exocrine Glands - Endocrine Glands |
| What are exocrine glands? | Glands that secrete products into ducts and take those products to the lumen of organ, body cavity, or outer surface of the body |
| What are some examples of exocrine glands? | - Sweat glands - Sebaceous glands - Digestive glands - Mucous glands |
| What are endocrine glands? | Endocrine glands do NOT use ducts. They take contents DIRECTLY to interstitial fluid where it's diffused into the bloodstream |
| What are some examples of endocrine glands? | - Pituitary gland - Pineal gland - Adrenal gland - Thyroid gland |
| What are endocrine glands very dependent on? | The cardiac system, that is why they are so VASCULAR. |
| What does a hormone absolutely need for it to bind to a target cell? | Receptors |
| Why are receptors so necessary? | Because that is the middle man between the hormone and what it wants to effect. There must be receptors to connect the hormone to the target cell. |
| What is down-regulation? | When there is too much of a hormone, the number of receptors DECREASE. |
| What does it mean when there is a down-regulation of a hormone? | The target cells are LESS SENSITIVE to a hormone |
| What do synthetic hormones do? | Block the receptor that disallows the hormone to go through the normal functions |
| What are circulating hormones? | Hormones that go from secretory cells --> ISF --> Blood |
| How are circulating hormones inactivated and excreted? | Inactivated by the LIVER Excreted by the KIDNEYS |
| What are local hormones? | Hormones that either act on neighboring cells or on the SAME cell that secreted it |
| What piece of information stands out about local hormones? | They do NOT immediately enter the bloodstream |
| What are paracrine hormones? | Hormones that act on neighboring cells |
| What are autocrine hormones? | Hormones that act on the same cell that secreted it |
| What types of hormones have a larger abundance? | Circulating hormones |
| Which type of hormones stay in effect longer? | Circulating hormones |
| Which type of hormones are inactivated quickly? | Local hormones |
| What are 3 types of lipid-soluble hormones? | - Steroid hormones - Thyroid hormones - Nitric oxide |
| What are steroid hormones? | They are derived from cholesterol so they are very unique due to the different chemical attachments? |
| What is the result of steroid hormones having different chemical attachments? | Steroid hormones have several different functions |
| What is the difference b/w the Nervous and Endocrine systems regarding their target? | - The nervous system has a specific target while the endocrine system's target is a lot more broad |
| What characteristic makes a hormone a hormone? | For a chemical to be a hormone it has to travel in the BLOOD |
| What is a characteristic about hormone receptors? | They are very SPECIFIC to each and every hormone |
| What are natriuretic peptides? | They are responsible of stretching the heart walls to lower BP |
| What kind of hormone is histamine? | Circulating Hormone |
| What is a Thyroid hormone? | (T3&T4) Synthesized by attaching iodine to tyrosine |
| What are thyroid hormones responsible for? | Elevating all metabolic activity |
| What is a characteristic of lipid-soluble hormones? | They can go straight through the phospholipid bi-layer |
| Why can the ability of lipid-soluble hormones being able to go straight through the lipid-bilayer be a potential problem? | Because then cells become very susceptible to changes like organelle change and basically it has the ability to completely transform cells |
| What are the different types of water soluble hormones? | - Amine - Peptide - Protein - Eicosanoid |
| How are water-soluble hormones transported in the blood? | They flow freely |
| How are lipid-soluble hormones transported in the blood? | They are bound to transport protein |
| What organ synthesizes the transport protein? | Liver |
| What hormones can be taken by the mouth and why? | Steroid and thyroid hormones because since they are lipid-soluble they don't break down during digestion |
| What hormones must be injected directly to the blood stream? | Protein and peptide hormones (insulin) because the digestive enzymes would break down the peptide bonds b/c they're water-soluble hormones |
| The response to a hormone depends on what? | The hormone and the target cell |
| What is a characteristic about target cells? | That they can respond differently to the same hormone |
| What are the different effects of a hormone? | - They can make new molecules - Change permeability of plasma membrane - Transport substance in or out of target - Alter rate of metabolic rate - Contract smooth or cardiac muscle |
| How does a hormone announce its arrival? | It binds to its receptors |
| Where are the receptors for lipid-soluble hormones? | Inside target cells |
| Where are the receptors of water-soluble hormones? | They are part of the plasma membrane of the target cells |
| What is the 1st step of an lipid-soluble hormone acting on a target cell? | The hormone diffuses out of blood, into ISF and into the plasma membrane of the target cell |
| What is the 2nd step of a lipid-soluble hormone acting on a target cell? | The hormone binds to receptor in cytosol and hormone-receptor complex alters gene expression |
| How does the hormone-receptor complex alter gene expression? | By turning some genes of the Nuclear DNA on and some off |
| What is the 3rd step of a lipid-soluble hormone acting on a target cell? | The DNA is transcribed, mRNA leaves nucleus and finds ribosomes to produce new proteins |
| What is the 4th step of a lipid-soluble hormone acting on a target cell? | The new proteins alter the cell's activity to that of the hormone |
| What is the difference with water-soluble hormones? | Because they CANNOT cross a lipid-bilayer they have to bind to receptors on the outer surface of the target cell's plasma membrane |
| What is the 1st messenger? | When the hormone binds to a receptor at the outer surface of the plasma membrane |
| What is the 2nd messenger? | cAMP |
| What is the 1st step of a water-soluble hormone acting on a target cell? | Hormone diffuses out of blood and attaches to receptor on outer surface of membrane. Hormone-receptor complex activates G protein which in turn activates adenylate cyclase |
| What is the 2nd step of a water-soluble hormone acting on a target cell? | Adenylate cyclase converts ATP into cAMP |
| What is the 3rd step of a water-soluble hormone acting on a target cell? | cAMP (2nd messanger) activate protein kinases |
| What is the 4th step of water-soluble hormone acting on a target cell? | The protein kinases phosphorylate cellular proteins which turn some proteins on and some off (ATP donates the phosphate groups and converts to ADP) |
| What is the 5th step of a water-soluble hormone acting on a target cell? | Phosphorylated proteins cause reactions that produce physiological responses |
| What is the 6th step of a water-soluble hormone acting on a target cell? | Phospodiesterase deactivate cAMP which turns off the cell's response |
| How does the hormone response stop? | G protein is not being any further stimulated b/c hormone molecules are NOT binding to receptor, the G protein slowly inactivates which inactivates andenylate cyclase and the hormone response is stopped |
| What are cascades/chain reactions? | Hormones that still have effects even in low concentrations b/c there are steps that amplify the effect |
| The responsiveness of a target cell depends on what things? | - Hormone concentration in blood - Abundance of hormone receptors - Influences of other hormones |
| What 2 factors give a hormone a more vigorous effect? | - A higher level of hormones - Increase in receptors |
| What is a permissive effect? | The exposure to a hormone is required for another hormone to exert its full effects on a target cell |
| What is a synergistic effect? | When 2 hormones act together to establish a greater effect |
| What is an antagonistic effect? | 1 hormone opposes the effect of the other hormone (but it depends on what receptors you activate) |
| What is the difference between permissive and synergistic? | In a permissive effect, only that 1 hormone needs the other. With synergistic effects, both hormones need each other. |
| How is the ONLY way that hormones can be released? | By stimulation |
| How is hormone secretion regulated? | - Signals from NS - Chemical changes in blood - Other hormones |
| Most regulatory responses are based on what type of feedback? | Negative |
| What is the hypothalamus | It is the major link between the Nervous and Endocrine System |
| Why is the hypothalamus considered the "Master Gland"? | Because it synthesizes 9 hormones |
| What is the pituitary gland? | Pea-shaped structure attached to the hypothalamus by the infundibulum and is considered as a half neural and half endocrine gland |
| What is) the pituitary gland split up into? | - Anterior pituitary (adenohypophysis) - Posterior hypophysis (neurohypophysis) |
| Why is there a hypophyseal portal system only for the adenohypophysis? | Because the hypothalamus has releasing and inhibiting hormones that are responsible for stimulating or inhibiting hormones of the anterior pituitary gland |
| What are somatotrophs? | - Human growth hormone - Insulin-like growth factors |
| What are thyrotrophs? | TSH |
| What are gonadotrophs? | - FSH - LH |
| What are lactotrophs? | PRL |
| What are corticotrophs? | - ACTH - MSH (melanocyte-stimulating hormone) |
| How are the anterior pituitary gland hormones released? | They are stimulated by the releasing and inhibiting hormones of the hypothalamus |
| How are hypothalamic hormones sent to the anterior pituitary? | The hypothalamic hormones are in neurosecretory cells that get transported to the ant. pit. by the hypophyseal portal system |
| What are tropic hormones? | Anterior pituitary hormones that act on other endocrine glands |
| What are the hormones of the Anterior Pituitary gland? | - HGH - PRL - LH - FSH - ACTH - TSH -MSH |
| What does the HGH do? | Stimulates secretion of insulin-growth factors (IGFs) that promote, protein synthesis, transcription and translation |
| What does the TSH do? | Stimulates the synthesis and secretion of thyroid hormones in the thyroid gland |
| What does FSH do? | For women: ovaries start development of oocytes For men: testes start testosterone production |
| What does LH do? | For women: ovaries stimulate ovulation For men: stimulate testosterone production |
| Why can TSH go through lipid bi-layers? | Because of its proteinaceous shape |
| What is dwarfism? | Cannot produce or release HGH |
| What is gigantism? | When there is too much HGH secreted before the epiphyseal plate closes? |
| What is acromegaly? | When there is too much HGH being secreted AFTER the epiphyseal plate has closed |
| What is PRL? | Promotes milk secretion by mammary glands |
| What hormone allows milk to actually be released from the breast? | Oxytocin |
| What does ACTH do? | Stimulates the adrenal cortex hormones |
| What does MSH do? | Releases melanin to darken the skin to protect it from harmful UV rays |
| What does cortisol do? | Helps the body deal with stress |
| How does cortisol get released? | The hypothalamus stimulates a corticotropin releasing hormone that gets sent to the Pituitary gland and stimulates the ACTH to stimulate the andrenal glands to secrete cortisol |
| What is cushing's syndrome? | When there is either too much: - CRH - ACTH - Cortisol |
| What are symptoms of Cushing's Syndrome? | - Moon face - Red striations - Thin skin - Poor wound healing |
| What is Addison's Disease? | Defiency in either: - CRH - ACTH - Cortisol - Means they cannot deal with stress properly |
| What is special about the posterior pituitary hormones? | The posterior pituitary gland does NOT produce its own hormones, it just stores and releases the hormones that the HYPOTHALAMUS produced |
| What are the 2 hormones that are produced by the hypothalamus and released by the posterior pit. gland? | Oxytocin and ADH |
| What does Oxytocin do? | - Establish emotive attachment - Enhances smooth muscle contraction in wall of uterus (+ feedback) - Stimulates milk EJECTION from mammary glands |
| What does ADH do? | - Decreases urine production by causing the kidneys to return more water to the blood - Decreases water lost through sweating and contraction of arterioles which increases BP |
| What stimulates oxytocin? | Stretching of the uterus |
| The thyroid gland contains ______ that produces _______? | Thyroid follicles, T3&T4 |
| What do the thyroid hormones do? | - Increase BMR - Stimulate protein synthesis - Increase use of fatty acids and glucose for ATP production |
| T3 and T4 are what kind of hormones? | Lipid-soluble hormones |
| What is the other kind of follicular cells? | Parafollicular cells (C cells) that secrete Calcitonin which build bone and lower blood calcium levels (osteoblasts take Calcium make bone) |
| What are the 2 lobes of the thyroid gland connected by? | The isthmus |
| What does the bird flu cause? | A hyperrelease of thyroxin's |
| What type of effect would the thyroid hormones be considered as? | Permissive effect |
| What does vasodilation do in regards to ADH secretion? | Allows evaporation and gets rid of the heat due to perspiratoin |
| How is the secretion of the thyroid hormone controlled? | - Thyrotropin-releasing hormone from the hypothalamus - TSH from the ant. pit. - Situations where an increase ATP demands increase in thyroid hormones (thyroid hormones is what puts the ATP to use) |
| What is the process of Thyroid hormone regulation? | 1.) If T3&T4 levels are low or BMR is low, TRH is stimulated from the hypo 2.) Travels to ant. pit. to stimulate TSH 3.) TSH travels to follicular cells of thyroid glands (endocytosis) 4.) That stimulates the T3&T4 hormones to be produced and sent to the blood (exocytosis) 5.) Elevated levels of thyroid hormones inhibit TRH and TSH |
| What kind of feedback would thyroid regulation be considered as? | Indirect feedback |
| What is needed for thyroid hormones? | Iodine is needed to be transported to the follicles in order to make the thyroxins |
| What are some iodine deficiency disorders? | - Cretinism - Goiter - Exophthalmia |
| What does the PTH do? | - Regulates calcium phosphate and magnesium ions in the blood - Increases number and activity of osteoclasts - Elevates reabsorption of blood calcium - PTH BREAKS DOWN BONE |
| What happens if there is too much secretion of PTH? | - Not enough ossification, body becomes cartilaginous - Also causes osteoporosis |
| What are oxyphil cells? | Cells within the parathyroid glands that have no known function |
| What are the chief cells? | Cells in the parathyroid gland that get stimulated to release PTH |
| What happens when there is a high level of blood calcium levels? | 1.) Thyroid gland gets stimulated to secrete Calcitonin from its parafollicular cells 2.) It inhibits osteoclasts and stimulates osteoblasts to take the Ca+ and put it toward bones |
| What happens if there is a low level of blood calcium? | 1.) The parathyroid hormone will be stimulated to secrete PTH 2.) Will inhibit osteoblasts and stimulate osteoclasts to break down bone and increase blood Ca levels 3.) PTH also stimulates the release of Calcitriol from the kidneys which reabsorbs Ca from food |
| The adrenal cortex (outer region of adrenal gland) secretes what hormones? | - Aldosterone - Cortisol - Androgens |
| What does Aldosterone do? | Retains Na by dumping K to elevate BP |
| What does cortisol do? | Deals with stress |
| What are androgens? | Sex hormones that more readily build testosterone and have masculinizing effects |
| What is DHEA and what does it do? | It is meant for females to give them some testosterone if they are deficient |
| What happens if a man uses DHEA? | He can lose his hair |
| What does the adrenal medulla consist of? | Epinephrine and Norepinephrine which intensifies sympathetic responses |
| What are glucocorticoids? | Steroid hormones in the adrenal medulla that help with glucose homeostasis |
| What are mineralcorticoids? | Help with mineral homeostasis |
| What is Addison's disease? | When there is a deficiency in secretion of adrenal hormones |
| What is precocious puberty? | When young children develop secondary sex characteristics |
| What is the pancreas? | Both an endocrine and exocrine hormone |
| What do 99% of pancreatic cells produce? | Digestive enzymes |
| What kind of cells does the Islets of Langerhans produce? | - Alpha cells - Beta cells - Delta cells - F cells |
| What do alpha cells do? | They secrete glucagon which RAISES blood sugar |
| What do beta cells do? | They secrete insulin, which LOWERS blood sugar |
| What do delta cells do? | - Secrete somatostatin - Inhibit both insulin and glucagon |
| What do F cells do? | - Secretes pancreatic polypeptide - Inhibits somatostatin and secretion of digestive enzymes |
| What is the exocrine function of the islets of Langerhans? | Contains acini which contains digestive enzymes to breakdown food |
| What is the endocrine function of the pancreas? | Pancreatic islets that contain insulin and glucagon |
| What do hormones FSH and LH do? | - Regulate menstrual cycle - Maintain pregnancy - Prepare mammary glands for lactation - Maintains female secondary sex characteristics |
| What does inhibin do? | Inhibits FSH |
| What hormone is produced during pregnancy and what does it do? | Relaxin- allows pubic symphysis to become stretchy |
| What does the pineal gland secrete? | Melatonin which contributes to circadian rhythm |
| When is more melatonin liberated? | During darkness |
| What helps an individual get more melatonin? | Being in contact with full spectrum light |
| What is Seasonal Affective Disorder? | Causes an individual to have depression due to the low amount of melatonin in their system which causes them not to get enough sleep |
| What does the thymus do? | It secretes different thymosins that help with T cell maturation and helps with immune response |
| What happens to the thymus as a person gets older? | It involutes meaning it gets smaller and loses its function |
| What are the 2 kinds of stress? | - Eustress- helpful stress - Distress- bad stress |
| What happens when a person is going through stressful conditions? | The body initiates a stress response called general adaption syndrome (GAS) |
| What is the first stage of GAS? | Initial fight or flight response where Epinephrine, norepinephrine, and cortisol are secreted |
| What is the second phase of GAS? | Slower resistance reaction; the body begins to run out of cortisol |
| What is the 3rd phase of GAS? | Eventual exhaustion; the body completely runs out of cortisol and there is a homeostatic imbalance, potentially causing death |
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