The Endocrine System – Questions And Correct Answers

THE ENDOCRINE SYSTEM – QUESTIONS
AND CORRECT ANSWERS
WhyA2isA2theA2releaseA2ofA2acetylcholineA2atA2theA2neuromuscularA2junctionA2notA2conside
redA2aA2"hormonalA2event"?A2-A2Ans--
acetylcholineA2isA2aA2neurotransmitterA2releasedA2byA2aA2motorA2neuron

WhichA2systemA2producesA2aA2quickerA2response,A2theA2nervousA2systemA2orA2theA2endo
crineA2system?A2WhichA2systemA2producesA2aA2longer-actingA2response?A2-A2Ans--
(a)A2nervousA2system;
(b)A2endocrineA2system

HowA2doesA2aA2sudoriferousA2(sweat)A2glandA2differA2fromA2anA2adrenalA2gland?A2-A2Ans--
sweatA2gland:A2exocrineA2glandA2whichA2releasesA2itsA2secretionA2toA2theA2skinA2surfaceA2
viaA2aA2duct;A2adrenalA2gland:A2endocrineA2glandA2whichA2releasesA2itsA2hormonesA2intoA2
theA2blood

WhyA2areA2organsA2suchA2asA2theA2kidneys,A2stomach,A2heart,A2andA2skinA2consideredA2t
oA2beA2partA2ofA2theA2endocrineA2system?A2-A2Ans--
theyA2produceA2hormonesA2viaA2enteroendocrineA2cells

WhyA2wouldA2follicle-
stimulatingA2hormoneA2actA2onA2theA2ovariesA2butA2notA2onA2theA2thyroid?A2-A2Ans--
hormonesA2areA2targetA2specific,A2requiringA2specificA2receptorsA2forA2activityA2(function)

IdentifyA2theA2chemicalA2classesA2ofA2hormones.A2-A2Ans--lipid-
solubleA2(steroidA2hormonesA2andA2thyroidA2hormones);A2water-
solubleA2(amines,A2peptidesA2andA2proteins,A2andA2eicosanoids)

WhereA2doA2lipid-solubleA2hormonesA2bindA2toA2theirA2targetA2cells?A2WhereA2doA2water-
solubleA2hormonesA2bindA2toA2theirA2targetA2cells?A2-A2Ans--(a)A2withinA2theA2targetA2cell;
(b)A2onA2aA2receptorA2onA2theA2cellA2membrane

WhyA2isA2cyclicA2AMPA2consideredA2aA2"secondA2messenger"?A2-A2Ans--
itA2activatesA2inactiveA2enzymesA2inA2theA2cellA2toA2giveA2theA2responseA2attributedA2toA2th
eA2hormone

WhatA2factorsA2determineA2theA2responsivenessA2ofA2aA2targetA2cellA2toA2aA2hormone?A2-
A2Ans--
hormoneA2concentration,A2abundanceA2ofA2targetA2cell'sA2hormoneA2receptors,A2influence
A2exertedA2byA2otherA2hormones

, WhatA2areA2theA2threeA2influencesA2overA2hormoneA2secretion?A2-A2Ans--
signalsA2fromA2theA2nervousA2system,A2chemicalA2changesA2inA2theA2blood,A2otherA2horm
ones

WhatA2isA2theA2functionalA2importanceA2ofA2theA2hypophysealA2portalA2veins?A2-A2Ans--
theyA2areA2theA2directA2routeA2takenA2byA2hypothalamicA2hormonesA2toA2actA2immediately
A2onA2anteriorA2pituitaryA2cells,A2beforeA2theA2hormonesA2areA2dilutedA2orA2destroyedA2inA2t
heA2generalA2circulation

WhichA2anteriorA2pituitaryA2hormonesA2stimulateA2aA2secondA2endocrineA2glandA2toA2relea
seA2aA2hormone?A2-A2Ans--FSH,A2LH,A2TSH,A2ACTH

YouA2haveA2noticedA2yourA2neighbor'sA28-year-
oldA2childA2isA2theA2sameA2heightA2asA2herA25-year-
oldA2cousin.A2ThisA2childA2couldA2beA2deficientA2inA2whichA2hormone?A2-A2Ans--hGH

IfA2aA2personA2hasA2aA2pituitaryA2tumorA2thatA2secretesA2aA2largeA2amountA2ofA2hGHA2andA
2theA2tumorA2cellsA2areA2notA2responsiveA2toA2regulationA2byA2GHRHA2andA2GHIH,A2willA2h
yperglycemiaA2orA2hypoglycemiaA2beA2moreA2likely?A2ExplainA2yourA2answer.A2-A2Ans--
Hypoglycemia

ExplainA2howA2bloodA2levelsA2ofA2T3/
T4,A2TSH,A2andA2TRHA2wouldA2changeA2inA2aA2laboratoryA2animalA2thatA2hasA2undergone
A2aA2thyroidectomyA2(completeA2removalA2ofA2itsA2thyroidA2gland).A2-A2Ans--
lowA2bloodA2levelsA2ofA2T3A2andA2T4A2wouldA2stimulateA2increaseA2inA2levelsA2ofA2TRH,A2w
hichA2wouldA2stimulateA2increasedA2levelsA2ofA2TSH;A2however,A2removalA2ofA2theA2thyroi
dA2glandA2wouldA2preventA2productionA2ofA2T3A2andA2T4

WhereA2areA2theA2hormonesA2secretedA2byA2theA2posteriorA2pituitaryA2produced?
A2HowA2doA2OTA2andA2ADHA2getA2fromA2theirA2productionA2siteA2toA2theA2capillariesA2ofA2th
eA2posteriorA2pituitary?A2-A2Ans--(a)A2hypothalamicA2neurosecretoryA2cells;
(b)A2theyA2areA2packedA2intoA2vesiclesA2andA2transportedA2downA2theA2axonsA2toA2theA2ax
onA2terminalsA2inA2theA2posteriorA2pituitaryA2untilA2exocytosisA2isA2triggered,A2thenA2theA2h
ormonesA2areA2releasedA2andA2diffuseA2intoA2theA2capillariesA2ofA2theA2posteriorA2pituitary

Functionally,A2howA2areA2theA2axonsA2ofA2hypothalamicA2neurosecretoryA2cellsA2andA2theA
2hypophysealA2portalA2veinsA2similar?A2-A2Ans--
bothA2areA2directA2routesA2forA2hormoneA2releaseA2thatA2doA2notA2involveA2theA2generalA2c
irculation

IsA2OTA2regulatedA2byA2positiveA2orA2negativeA2feedback?
A2WhatA2feedbackA2stimuliA2influenceA2theA2releaseA2ofA2OT?A2-A2Ans--
(a)A2positiveA2feedback;
(b)A2stretchingA2ofA2theA2cervixA2andA2suckling