Lec 25 Adrenal Flashcards
What causes adrenal cortex to release cortisol?
ACTH from anterior pituitary
What is feedback of adrenal cortex of anterior pituitary?
negative feedback
What happens if you give intravenous cortisol?
turn off normal pituitary ACTH
What happens if you give intravenous ACTH?
cause cortisol secretion from adrenal cortex
What is the pro-hormone for ACTH? wht else does it make
pro-opiomelanocortin
- also makes B lipotropin
- gamma lipotropin
- B endorphin
What is effect on melanocytes of lack or cortisol/diseased adrenal cortex?
- pro-hormone for ACTH also makes alpha-MSH normally in small dose
- if no cortisol, don’t get neg feedback on ACTH so have extra high levels
- get extra stimulation of melanocytes
- get melanogenesis
How do you get from cholesterol to cortisol
5 steps
- side chain cleavage from cholesterol
- several modifications [3 hydroxylations]
What is Pregnenolone? possible use?
- universal precursor of steroid hormones
- protects brain from cannabis intoxication
What is common deficiency that causes block in generation of cortisol? what do you get build up of?
21-hydroxylase deficiency
get build up of progesterone
What is effect of cortisol?
mobilizes glucose from fat, muscle
dissolves muscle
maintains normal glucose levels and normal BP
in good amount good for bone [in too much, dissolves bone]
keeps us from having too much inflammation
When is cortisol peak? what is meaning of zero at night? zero at morning?
6-8am when you are waking up
zero at night = normal
zero at morning can kill
what happens if too much cortisol?
- bad for emotions, depression
- osteoporosis
- cardiac hypertrophy [hypertension]
buffalo hump = redistribution of fat
diabetes [rasies glucose]
obesity
amenorrhea
muscle weakness
skin is thin and flushed
get stria on stomach
What are the zones of adrenal cortex and which make which hormones?
out to in
zona glomerulosa: mineralcorticoids [salt]
- aldosterone
zona fasciculata: glucocorticoids [sugar]
- cortisol
zona reticularis: androgens [sex]
what does adrenal medulla make?
catecholamines
what does aldosterone do? what causes it to act?
needs a little ACTH to start it but mostly stimulated by Renin
keeps Na in body, gets rid of K
the boss of aldosterone is the kidney [RAAS]
salt and aldo feedback on kidney to shut down renin/kidney
