Adrenal Gland Flashcards
blood goes from out to in of the adrenal gland.. what does that tell you about bathing in the medulla?
cortisol bathes the medulla
Zona fasciculate and zona reticularis can do what?
Zona reticularis releases what?
they both can release androgens and glucocorticoids.
DHEA –> sex androgens.
of the medulla, what’s the main product of the two?
epinephrine, not NE.
What stimulates catecholamines production?
ACh
Where does the medulla come from? cortex?
neural crest
mesoderm
pathway of HPA axis for cortisol?
what is the negative feedbacks?
Hypothalamus releases CRH –> gets to the AP activating corticotrophs releasing ACTH –> targets the adrenal gland –> creates cortisol and androgens
Cortisol will negatively regulate the Anterior pituitary (ACTH) and negatively regulate hypothalamus (CRH)
cortisol and the liver (think of the name of cortisol)
cortisol on muscle?
cortisol on adipose?
cortisol and the immune system?
Cortisol is a glucocorticoid, raising blood glucose levels at the level of the liver, promoting GNG! (glucagon like actions, anti insulin actions)
promote muscle degradation to generate acids
promote adipose tissue breakdown to produce more fatty acids
immune suppression
What is the main stimulus CRH from the hypothalamus?
Physical/Psychological Stress (exercise being physical) and Circadian Rhythm (SCN)
Cortisol secretion is happening most at what time?
what kind of manner?
pulsatile manner, and highest secretions are around when you wake up.
whenever you order lab tests, you need to know when cortisol is elevated and the ranges.
for the most part, boost is happening mostly around 8 early in the morning (20mg/dL).
Exogenous cortisol therapy?
what does it do to the system? (include the axis)
what if we measure glucocorticoids?
what about the target tissue?
most potent glucocorticoid?
we can put in synthetic / analog glucocorticoids that are given.
when they’re given, it’ll be a negative feedback mechanism decreasing CRH, decreasing ACTH.
cortisol will be decreased because of ACTH.
higher levels of glucocorticoids.
target tissue will be up taking it more!
most potent is dexamethasone, least is prednisone
What happens if you down regulate ACTH on Aldosterone?
changes in ACTH will not affect chronic change in aldosterone (remember that’s the RAAS pathway)..
angiotensin 2 from renin and elevated potassium are what stimulating it.
ACTH is a weak stimulator but not crucial
main stimulus of aldosterone? (3)
Angiotensin 2 from renin
and elevated potassium, decreased Na in the blood.
where is renin coming from? what makes this structure make it?
pathway?
what happens when we have the angiotensin 2?
KIDNEY
low BP –> the kidney –> makes renin –> makes Angiotensin 1 (using angiotensinogen from the liver)–> ACE converts it to angiotensin 2
angiotensin 2 goes to the cortex –> release aldosterone –> increase water/Na absorption –> increases BP!
frequent bruising with slow healing, backaches, excessive sweating, rapid weight gain..
face looks swollen compared to her body. sounds depressed, arms and legs are thin
low ACTH but high cortisol secretion
Cushing syndrome –> moon face / buffalo hump
hypercholesterol levels
abnormal glucose test and Cushing’s syndrome?
if you have an abnormal test, you would have insulin resistance because we normally have a hyper secretion of glucose due to cortisol levels being up
how do you know that Cushing’s syndrome isn’t from the pituitary gland?
there wouldn’t be a hyper excretion of ACTH, it would be lower because of the cortisol levels. so it has to be an adenoma in the adrenal gland.
for someone with Cushing’s syndrome, what’s the point of the dexamethasone test?
Inhibits ACTH so you know it’s not from the anterior pituitary and that it’s from the adrenal gland.
Cushing syndrome typical presentation?
what happens with the upper body?
face?
back?
what about their skin morphology?
Truncal obesity Moon face Buffalo Hump (supraclavicular inflammation) Easy bruising Hypertension
What is the low dose of dexamethasone?
low dose –> differentiating patients who have Cushing syndrome or not –> if you don’t have ACTH suppression would indicate CS.
test isn’t specific for telling you where the ACTH is coming from!!