endocrine system Flashcards
function of endocrine system
regulates long term processes eg growth, reproduction
main glands
hypothalamus
pituitary
parathyroid
pineal
thyroid
adrenal
pancreatic islets
organs with secondary endocrine function
heart
adipose tissue
reproductive organs
endocrine glands structure
ductless
endocrine cells
good blood supply
hormones process
bind to receptors in target cells. if not receptors, no response
hormones process
bind to receptors in target cells. if not receptors, no response
anabolic steroids
have receptors in muscle that stimulate muscle protein production
not all build muscle
risks of anabolic steroids
early skeletal and sexual maturation
damage to liver, CV system
high cholesterol
reduced sperm
facial hair
risks of anabolic steroids
early skeletal and sexual maturation
damage to liver, CV system
high cholesterol
reduced sperm
facial hair
3 types of hormones
AA derivatives - small
peptide hormones - chain of AA
lipid derivatives - steroid and eicosanoids
AA derivatives (tyrosine)
thyroid and catecholamines
AA derivatives (tryptophan)
melatonin
peptide hormones
insulin
oxytocin
glucagon
what hormones are lipid soluble
lipid and AA derivatives
what hormones are water soluble
all
2 locations of receptors
on cell membrane triggers signalling cascade for non lipid hormones and peptide hormones
inside cell - steroid and thyroid as lipid soluble
activation of cAMP
activated G protein activates enzyme adenylate cyclase
adenylate cyclase converts ATP to cAMP
cAMP (second messenger) activates kinase enzyme
affects target cell
how the same hormone can have a different affect on different target cells
adrenaline binding to beta receptors increase cAMP
binding to alpha breakdown cAMP
steroid hormone action
diffuse through cell
binds to receptor inside
complex into nucleus
binds to dna
activated genes
produce proteins from mRNA
thyroid hormone action
into cell
binds to receptors at mitochondria and nucleus
binds to dna
gene activation
what happens to free hormones
remain functional for less than an hour
bind to target cell receptors or broken down in liver or enzymes
thyroid and steroid hormones when not used
remain in circulation longer
enter bloodstream for longer
hypothalamus
interface between nervous and endocrine system
regulate hormones affect pituitary function
pituitary anterior
hormones that control other organs
