22.3 Adrenal Hormones Flashcards
What is the function of the adrenal medulla?
- secrete epinephrine and norepinephrine
2. participate with the sympathetic response system
What type of hormones are secreted from the cortex of the adrenal gland directly in to the blood?
- mineralcorticoids
- glucocorticoids
- androgenic hormones
What layer are the cortisol and androgens secreted from?
- cortex, made of the zona fasciculata and zona reticularis
What area of the adrenal gland is the catecholamines secreted from?
- adrenal medulla
What is the rate limiting step for forming corticosteroids from cholesterol?
- cholesterol desmolase
What will increase the LDL receptors that will contribute to increasing the production of corticosteroids?
- Adrenocorticothyroid hormone, with angiotensin II increase conversion of cholesterol to pregnenolone
What is the main glucocorticoid?
cortisol, generally released in response to stress
WHat controls the release of cortisol?
adrenocortiotropic hormone from the anterior pituitary gland. This upregulates its own receptor and will increase the release of cAMP/
Where is cortisol secreted from?
zona fasciculata of the adrenal cortex.
When is cortisol highest in concentration and lowest in concentration?
- highest before waking
2. lowest in the evening
What group of hormones can dehydroepiandrosteron and androstenedione clumped into?
- androgenic hormones
18-carbon steroids have what type of activity?
- estrogenic activity
19-carbon steroids have what type of activity?
testosterone activity
Where are the androgenic hormones secreted from?
zona reticularis
What can lack of aldosterone lead to?
- death due to lack of mineralocorticoids and electrolyte imbalance
Why are mineralocorticoids important for survival?
- prevent increased levels of potassium, and loss of NaCl.
- this will prevent hypovolemic shock
- also prevents hyperkalemia and cardiac toxicity as secondary symptom/sign
What is the effect of excess aldosterone secretion?
- increased arterial pressure
- hypokalemia, muscle weakness
- increas potassium transport into cell bodies generating alkalosis, by exchanging H ion for K ion in intercalated cells.
What is the primary function of glucocorticoids?
- initiate gluconeogenesis.
2. increases lipolysis
What is secreted from the zona glomerulosa?
- mineralocorticoids, regulate BP and electrolyte balance
Corticosteroids are derivatives of what and attach to what?
- form from cholesterol and attach to coated pits
What must be present to convert cholesterol to corticosteroids?
- sholesterol desmolase (rate limiting step) which produces pregnenolone in the mitochondria
What can increase the activity of cholesterol desmolase?
ACTH, and angiotensin II. produce more pregnenolone
What effect will mineralocorticoids have on electrolytes?
- sodium reabsorption increased
- hyperkalemia increases aldosterone
- aldosterone increases potassium secretion by kidney
- aldosterone increase H ion secretion by kidney
What controls the secretion of mineralocorticoids?
- angiotensin II and potassium
