Pituitary adrenal axis Flashcards
what is the adrenal gland consisted of
cortex and medulla
what are the hormones of the adrenal gland used for
regulators of metabolism and adaptation to stress
what is cortisol and what does it do
glucocorticoid and increases plasma glucose levels
a deficiency in cortisol leads to what
hypoglycaemia
what is aldosterone
mineralocorticoid
what does aldosterone do
promotes salt and water retention by the kidney
what else does the adrenal cortex synthesise and secrete and what are they converted to
androgenic steroids
converted by peripheral tissue to testosterone
what is the primary product of chromaffin in the medulla
adrenaline, also produces adrenaline precursor
noradrenaline
[catecholamines]
name the layers of the adrenal gland, outside -> in
capsule
zona glomerulosa
zona fasciculata
zona reticularis
medulla
what zona is responsible for producing aldosterone
zone glomerulosa
what zona is responsible for producing cortisol
zona fasciculata
what zona is responsible for producing weak androgens
zona reticularis
what do aldosterone, cortisol and weak androgens all have in common
they’re all steroid hormones
(1)MODULATING OUR STRESS RESPONSE
stressful stimuli causes what in the hypothalamus
to activate the adrenal cortex via hormonal signals
(2)MODULATING OUR STRESS RESPONSE
adrenal cortex secrets what and why
mineralocorticoids and glucocorticoids
because the adrenal cortex was sent stimuli (activating it) by the hypothalamus via hormonal signals
what are effects of mineralcorticoids
retention of water ions and water by kidney
increased blood volume and blood pressure
what are effects of glucocorticoids
proteins and fats are broken down and converted t glucose, leading to increased blood glucose
partial suppression of immune system
what are all steroid hormones derived from
cholesterol
what binding globulin transports cortisol
corticosteroid binding globulin
enzymes which produce steroid hormones from cholesterol are located where
mitochondria and SmER
what is the rate limiting step in converting cholesterol to steroid hormones and what protein carries out this step
transport of free cholesterol from the cytoplasm into the mitochondria
StAR -> moves cholesterol from outer membrane to the inner membrane where cholesterol is converted t pregnenolone (precursor)
in the adrenal cortex how many pathways can pregnenolone be converted to
3
mineralocorticoids
glucocorticoids
androgens
adrenal steroidogenesis
what determines which pathway is taken
Each step of the pathway is regulated by a specific enzyme.
Different zones of the adrenal cortex have different relative activities of enzymes, resulting in different chemical reactions taking place.
liver is predominant site of what
steroid inactivation
