Detailed Grade 12 IEB Life Sciences Endocrine System notes, crafted by a matriculant who achieved a Life Science Distinction. These thorough and easy-to-understand notes cover all essential topics, making complex concepts simple. Ideal for exam prep and mastering the IEB curriculum!
endocrinevsexocrine atthebaseofthebrainattachedtothehypothalamus
located
ductlessglandsthat that
h ormones glands
release via
theirsecretions
release 2 a
lobes lobe
nterior posterior
directly the
into blood
stream ductstoabodycauityoroutsi.de viabloodvesselsanterior
connected
vianeuronsposterior
endocrine nervous worktogether
systems tobringforthhomeostasis to lobes
produceshormones posterior forstorage
Homeostasismaintenance of constantinternalequilibriuminthebody thehypophysisbysecretingreleasingfactors
controls
to
stimulatehypophysis produce
h ormones intoblood
HORMONES
hHknas cretedinsmal
chemical
gonic messengers areproteinssomearesteroidst.li
hormones
to via
quantities transported target
organ bloodstream
7TSHstimulatesthyroidtosecrete
hormonethyroxin 7ADHproducedbyhypothalamus
ve function
regulatory
by specifichormone
affected
Gorgan 2LH of
ovulation development corpusluteum
stimulates the
controls
of
reabsorption water
stimulatingor
inhibiting of
stimulatescells Leydig to testosterone
produce ducts tubulesmore towater
permeable
tveor.vefeedbackmechanismanydeviationfromnormallevelselicit responsethat 3FSHstimulatesdevelopmentofprimarypolicies ADHhelps
conservewater
restoresnormallevels activatesgerminal
epitheliumproduces
sperm
byhormonesintheblood
coordinationcontrolcoordinationbrought
mical 4 Prolactinstimulatesmammary to
milk
glands produce 2Oxytocinproducedinhypothalamus releasedbypo
issues
CONTROLOVERHORMONESHORMONAL diabetes
D ISORDERS IMBALANCES.es thyroid
of
5GrowthHormonepromotesgrowth muscles skeleton by ionsnecessaryfor
stimulatingproteinsynthesis con
causes the
birth
process
to moreoxyto
TFleshypophysis release
DISORDERSabnormalsecretion growth of
hormone feedback
positive m echanism
Dwarfism undersecretion
ofgrownthnfgmggyinki.gg inerlevelsof1hormonestimulatesthe
release
olobesoneithersideoftracheo.underlr ynx.produces secretes
hormone
thyroxin ofgrowt
Gigantism oversecretion
ofthe
more samehormone
iodineisessentialforthyroxinproduction's Acromeglyoversecretionof inadults
hormone
growth
yroxinFunctions
herbasalmetabolicrate normal of
growth development organs
orbreathing heartrate of
normalfunctioning nervous
system oversecretionofthyroxinhyperthyroidism undersecretionhypothyroidism
rate weightloss
fifffiffYfffih
incrmetabolic
irritability incr rote.resp.ra.es ffm ffhfm
ountofthyroxininboodiskeptconstantby.ve feedback
AsthyroxinelevelsinblooddropbelownormalhypophysissecretesmoreTSH
TSHstimulatesthyroidtosecretemorethyroxine thyroxinelevelsincrease
ifthyroxinlevelsriseabovenormal secretionofTSHisinhibited HORMONES
loweredTSHlevels resultindecreasedthyroxineproduction endocrine alphacellsproduceglucagon increaseglucoselev
if s L b
ucagon
fine cellsproduceinsulin decreaseglucose
beta levels
Diabetesmellitus
metabolic
diseasecharacterised byhighglucoselevelsinblood pancreasdoesn't
produce insulin
enough tolowerglucoselevels
chronic incurable hyperglycemia remaininb
body d
cells on't
receive
e to
glucose
nough release through
energy blood
high l
glucose evels
d raw out
water body dueto
the cells osm
cellrespirationfor
bodytofunction in
resulting dehydration
Type I diabetes coma Indness in failure cardiovascular
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