Adrenal Glands Flashcards
General Role of Adrenals
and location
Located on kidneys,
play major role in response to stress
Adrenal cortex stimulated by ….. releases…….
Adrenal Cortex- 80% of weight-
stimulated by ACTH from pituitary gland
- Zona glomerulosa- aldosterone
- Zona fasciculata- cortisol, cortisone and corticosterone
- Zona reticularis- aldosterone, androgens and estrogens, and glucocorticoids
**we will not be asked which zona produces what?
Adrenal Medulla stimulated by ….. releases…….
Adrenal Medulla- stimulated by sympathetic nervous system
Secretes epinephrine and norepinephrine
- What percentage of epi and norepi are from the chromaffin cells of the Adrenal Medulla?
- What percentage is found nerve terminals?
Why do we care?
- 30% of epi and nor epi are from the adrenal medulla
- 70% of epi and norepi are found in nerve terminals
The epi and norepi coming from the adrenal medulla are sectreted into the blood stream and considered hormones.
The 70% of epi and norepi found in the nerve terminals are considered neurotransmitters.
This is why epi and norepi are each considered both a hormone and neurotransmitter
What is a reason that epi and norepi being considered both a neurotransmitter and hormone is good (according to Dr. T)?
The redundancy allows us to still make these important substances if something stops working (like the adrenal gland)
What are the three categories of hormones secreted by the adrenal cortex?
Glucocorticoids
Mineralcorticoids
Adrenal estrogens and androgens
What is the most important glucocorticoid?
Cortisol
what are three roles of cortisol?
Metabolic
Anit-inflammatory
Growth-Suppressing
Explain the metabolic role of cortisol
What are 4 big effects we may see?
–Metabolic- stimulates protein catabolism (connective tissue breakdown) and glucose formation (increases fat deposition, especially abdomen, cheeks, supraclavicular)
•May have
- severe muscle wasting,
- diabetes,
- ovarian disease,
- obesity
Explain the anti-inflammatory role of cortisol
What big effects may we see?
What did dr. t remind us of?
–Anti-inflammatory-
- decrease T cell formation and function,
- suppress cytokines (immune response),
- stabilize lysosomes;
may see poor wound healing
If given as an anti-inflammatory, will shut down everything down below it in the inflammatory cycle/cascade (such as when comparing it to NSAIDS)
Explain the growth-suppressing role of cortisol
What big effect may we see?
–Growth-suppressing-
- inhibition of bone formation,
- lead to osteoporosis
May see pathological fractures
What is the main Mineralocorticoid relased by the adrenal cortex?
aldosterone
What are two main functions of Aldosterone?
conserves sodium
inhibits reabsoprtion of potassium (rids body of potassium)
Aldosterone: What is the purpose of conserving sodium and eliminating potassium?
–Conserves sodium, thereby increasing blood volume
- •Renin-angiotensin-aldosterone system (RAAS, or RAS) – regulates blood pressure and fluid balance, stimulated by low blood pressure
–Inhibits renal reabsorption of potassium
Aldosterone: how is this hormone related to pharma blood pressure control
•Potassium sparing drugs can be used to control BP
Wikipedia says they also promote excretion of sodium
Drugs that interfere with the secretion or action of aldosterone are in use as antihypertensives, like lisinopril, which lowers blood pressure by blocking the angiotensin-converting enzyme (ACE), leading to lower aldosterone secretion. The net effect of these drugs is to reduce sodium and water retention but increase retention of potassium. (wikipedia)