the endocrine system exam practice questions And Answers Correctly Defined Graded A+.

the endocrine system initiates responses ______. They are _____ duration responses. It acts via _____ released into the blood. Acts as _______ locations. Targets can be _____ in blood. Hormones act over ______ distances. - correct answer slowly, long, hormones, diffuse, anywhere, long What are the two kinds of glands? - correct answer exocrine- sweat, saliva, to membrane surface endocrine- produces hormones but lacks ducts What is the nueroendocrine organ? - correct answer the hypothalamus what are the endocrine glands? (5) - correct answer thyroid, adrenal, parathyroid, pineal, pituitary organs containing endocrine cells in the tissue? (3) - correct answer pancreas, testes and ovaries, placenta endocrie cells are also found where? (6) - correct answer adipose cells, thymus, small intestine, stomach, kidneys, heart What are hormones? - correct answer chemical substances released by cells to regulate cell metabolsim either amino acid based or steroidal what do hormones do? (5) - correct answer change plasma membrane permability stimulate protein synthesis (actin and myosin) activate or deactivate enzymes influence secretion of molecules from cells stimulate mitosis are amino acid hormones water soluble or insoluble - correct answer water soluble (loving), lipid insoluble (hating) Can amino acid based hormones cross the plasma membrane? - correct answer no, they cannot get through plasma membrane how do amino acid based hormones travel? - correct answer usually coupled via regulatory molecules called G proteins to one or more intracellular second messengers, which mediate the target cells response Receptors for water soluble hormones must be in what - correct answer plasma mebrane since these hormones cannot diffuse across plasma membrane explain the steps of the cyclic AMP signaling mechanism (amino acid based) (5) - correct answer 1. hormone binds to its receptor in plasma mebrane 2. receptor activates G protein which allows GDP to be replaced by GTP (high energy) 3. G protein activates adeylate cyclase (Gs stimulates enzyme and Gi inhibits) 4. Adenylate cyclase converts ATP to AMP (as long as Gs is binded to enzyme) 5. cAMP activates protein kinases (enzymes that phosphorylate) sterioid hormones are ______ loving and water _______. - correct answer lipid loving, water hating what are the steps of steroid and thyroid hormones - correct answer 1. diffuses easily across plasma mebrane 2. binds to intracellular receptor complex 3. hormone receptor complex moves into the nucleus and binds to DNA HRE, stimulating transcription 4. mRNA moves into cytoplasm where it is translated into a protein what are the three types of stimuli that cause release of hormones? - correct answer 1. humoral- released in direct response to levels of molecules or ions in blood 2. neural- nerve activity stiumlates release 3. hormonal- hormone from one gland casues another hormone to be released fro another gland what are target cells? - correct answer the tissue cells that hormones affect example of target cell - correct answer only cells of adrenal cortex have ACTH receptors The response of the target cells depends upon: (3) - correct answer -blood levels of the hormone -number of receptors on target cell - affinity of binding between hormone and receptor receptors are dynamic and can change in both: - correct answer number (up/down regulation) and affinity (high/low state) what is up-regulation - correct answer The number of receptors in the target site increases. This can occur when hormone levels are low and the cell is trying to produce a response to the hormone what is down-regulation - correct answer number of recpetors is decreased. This can occur when hormone levels have been high and the cell wants to reduce its response to the hormone what happens in a high affinity state - correct answer the receptor has a strong attraction for the hormone (very good lock and key fit) in a high affinity state the receptors are ______ efficient and _____ necessarily need as much hormone for _____ activation. - correct answer very, do not, full what happens in a low affinity state? - correct answer the receptor has a weak attraction for the hormone (not a good lock and key fit) in a low affinity state the receptors are ______ efficient and _____ need more hormone for _____ activation. - correct answer less, may, full if a hormone is ______ ______ it is transported free in blood; their target organ is usually ______. - correct answer lipid insoluble (all other hormones); rapid if a hormone is ______ ______ it is transported in blood attached to a protein; their target organ effect takes ______. - correct answer lipid soluble (steroids and thyroid); hours to days what is a half life - correct answer the length of time it takes for the level of a hormone to decrease by half in the blood which hormones have the shortest half-life - correct answer lipid insoluble (amino acid based) what kind of interaction of hormones is it when there must be more than one hormone present for full target cell response? Ex. GH and TH both must be present for normal bone growth and development - correct answer permissiveness what kind of interaction of hormones is it when more than one hromone produces the same effects but together their effect is much larger? Ex. glucagon and epinephrine raise blood glucose but together they raise it much more. - correct answer synergism what kind of interaction of hormones is it when one hormone opposes the action of another? Ex. calcitonin lowers blood calcium and parathyroid hormone raises it - correct answer antagonism the pituitary gland is also called what? - correct answer hypophysis the posterior pituitary is ______ tissue and anterior is _______. - correct answer neural, glandular what is the main function of posterior pituitary? - correct answer hormone storage area, releases meurohormones made in the hypothalamus (does not itself make hormones) how do neurohormones travel from hypothalamus to posterior pituitary? (4) - correct answer 1. hypothalamic neurons make oxytocin and ADH in the hypothalamus 2. hormones are trasnported down the axons of the hypothalamic-hypophyseal tract to the posterior pituitary 3. hormones are stored in axon terminals of the posterior pituitary 4. action potentials cause the release of hormones into the blood oxytocin is made in the _____ nucleus and ADH is made in _______ nucleus - correct answer paraventricular, supraoptic what is purpose of oxytocin - correct answer released in high amounts during childbirth and nursing mothers stimulates uterine contractions and milk ejection both actions are a result of positive feedbacks mechanisms what is purpose of ADH - correct answer stops urine production osmoreceptors in hypothalamus montior blood if blood becomes too concentrated (dehydration) what happens? - correct answer -osmoreceptors send impules to supraoptic nucleus -ADH is synthesized and released -ADH goes to kidney tubules and causes water to be reabsorbed and less urine is produced what are other triggers that release ADH? - correct answer pain, low BP, nicotine, morphine what is vasoconstriction? - correct answer when BP is very low ADH is released in large amounts and binds to recpetors on vascular smooth muscle ADH pathology - correct answer - alcohol inhibits ADH secretion causing an increase in urine output -diabetes insipidus (large urine output and intense thirst) The hypophyseal portal system consists of - correct answer primary capillary plexus, hypophyseal portal veins, secondary capillary plexus what does The hypophyseal portal system do? - correct answer carries releasing and inhibiting hormones to the adrenohyposis (anterior pituitary) to regulate hormone secretion what are the 6 major hormones of the anterior pituitary? which are trophic and nontrophic? - correct answer Four are trophic- TSH, ACTH, FSH, LH 2 are nontrophic- GH and prolactin what does trophic and nontrophic mean? - correct answer trophic- they regulate the secretory action of other endocrine glands which will then produce the final hormone nontrophic- they are the final hormone What is GH produced by? - correct answer somatotropic cells