exam 2 adrenal hormones (quiz 2 info) Flashcards
what is essential for life?
what is not essential for life?
is= adrenal cortex
isnt= adrenal medulla
what 3 things does the adrenal cortex secrete
- corticosteroids (cortisol)
- mineralocorticoids (aldosterone)
- sex hormones (DHEA)
20-30% of adrenal gland tissue and helps to prepare individual to deal with emergencies
adrenal medulla
what does the adrenal medulla secrete in response to sympathetic NS stimulation?
EPI and NE
3 layers of cortex from most outer to inner:
outer:
1. zona glomerulosa-> mineralocorticoids
- zona fasciculata (largest)-> glucocorticoids
- zona reticularis-> androgens
what is mineralocorticoids secretion regulated by?
(zona glomerulosa)
renin-angiotensin-aldosterone system (RAAS)
(aldosterone)
what is glucocorticoids secretion regulated by?
(zona fasciculata)
hypothalamic-pituitary-adrenal axis (HPA)- CRH, ACTH
(releasing cortisol)
what is androgens secetion regulated by?
(zona reticularis)
HPA also
(DHEA- sex hormones)
what cells secrete catecholamines EPI and NE into the blood?
chromaffin cells
adrenal cortex secretes hormones that are made from
cholesterol
aldosterone increases renal tubular reabsorption of ____ and secretion of ____.
leads to an increase in EC fluid volume and mean arterial pressure
reabsorption of Na+
secretion of K+
aldosterone secretion is stimulated by:
angiotensin II (releases when blood pressure is low)
increase K+
decrease Na+
aldosterone has similar effects on sweat glands and salivary glands as renal tubules.
increases Na and secretes K
effect on sweat glands important to:
effects on salivary glands
conserve body salt in hot environments
conserve na during high rates of salivary secretion
enzyme released by the cells in the kidneys in response to a variety of stimuli ex. sympathetic nervous system:
what are these cells releasing this enzyme?
renin
cells are juxtaglomerular cells
angiotensin II does:
-aldosterone secretion
-vasoconstriction
-thirst stimulation
-ADH stimulation
how do we get to angiotensin II?
angiotensinogen (inactive) to angiotensin I via renin enzyme
angiotensin I to angiotensin II via ACE enzyme
what is the enzyme converting angiotensin I to angiotensin II and is produced by endothelium
ACE (angiotensin converting enzyme)
causes:
-adrenal adenomal (benign)
-adrenal hyperplasia
-adrenal carcinoma (malignment)
INCREASE IN aldosterone (ALD)
primary hyperaldosteronism (Conn’s Syndrome)
signs and symptoms of Conn’s syndrom (primary hyperaldosteronism)
-hypertension
-hypernatremia (high Na)
-headaches
-potassium depletion (hypokalemia)
^ fatigue and weakness
-polyuria
-hypokalemic alkalosis
-LOW plasma renin (due to negative feedback= hypertension and high ALD)
treatment options of primary hyperaldosteronism (Conn’s Syndrome)
-surgical removal of tumor or most adrenal tissue when hyperplasia is caused
-medication antagonism of mineralocorticoid receptor
caused by decreased blood flow and pressure in renal artery
secondary hyperaldosteronism
CHF
cirrhosis
nephrosis
renal artery stenosis (decrease in blood flow to a kidney so the kidney thinks blood pressure is low= increase in renin)
secondary hyperaldosteronism
what is the cause of secondary hyperaldosteronism
high plasma renin activity
signs and symptoms:
-hypernatremia w/ ecf volume expansion
-edema
-decreased cardiac output
-similar to primary hyperaldosteronism
BUT high renin and not low
secondary hyperaldosteronism
what is secreted with any stress
cortisol
what does cortisol cause
mobilization of energy stores and suppresses immune response
when is cortisol peak?
secreted in CIRCADIAN RHYTHME
peaks in AM
types of stress that INCREASE cortisol release include:
-trauma of almost any kind
-infection
-intense heat or cold
-injection of NE
-surgery
-hypoglycemia
-stress
-debilitating disease
is the regulation of glucocorticoid secretion long or short negative feedback?
long bc cortisol is doing the feedback
what key things does cortisol do?
1
2
3
4
- gluconeogenesis (making new glucose)
- protein mobilization (protein catabolism/breakdown)
- fat mobilization
- stabilizes lysosomes (inhibits immune system activity)
when ACTH is secreted from the anterior pituitary, several other hormones are secreted as well bc the gene for ACTH forms a larger protein:
a preprohormone called POMC- Proopiomelanocortin
POMC cleaves into ACTH and:
-melanocyte stimulating hormone (MSH)
-B-endorphin
-B-lipotropin