Lecture Quiz 9 Flashcards
(44 cards)
Where are the adrenal glands located?
Superior and slightly medial to the kidneys
sometimes called suprarenal glands
Briefly describe the anatomy of the parenchyma of the adrenal gland
has a superficial layer - cortex
has inner part - medullar
What are the three zones of the adrenal cortex?
zona glomerulosa - outer zone
zona fasciculata - middle layer
zona reticularis - inner most layer
What does the adrenal medulla do?
acts as a separate endocrine gland from cortex produces catecholamines (epinephrine and norepinephrine)
How is the adrenal medulla stimulated?
by the nervous system
What does the zona glomerulosa release in general and what is the main example of one?
mineralcorticoids
regulate electrolytes in the extracellular space
aldosterone
What does Aldosterone do and what are the effects?
activates the gene for Na/K-ATPase in the kidneys
causes increase in Na+ reabsorption
causes K+ excretion/decrease in K+ reabsorption
water retention
How does aldosterone cause water retention and what does it result in?
water follows the sodium
helps make concentrated urine
causes increase in blood pressure
How is aldosterone regulated?
humoral regulation - Na+ and K+ ion concentration - low Na+ and high K+ stimulate production
hormonal regulation - renin-angiotensin causes production, induced by low blood pressure
atrial natriuretic peptide inhibits production - aorta stretched from water retention
ACTH has mild effect, causes secretion
What causes overproduction of aldosterone and what are the effects?
adrenal tumors
Conn’s syndrome
hypertension, edema, muscle weakness (K+ loss, no AP generated)
What does the zona fasciculata produce and what is the main example?
glucocorticoids
cortisol is the main example
What does cortisol do?
promotes formation of glucose from glycogen, fat, and proteins in response to increased fuel needs
inhibits immune reaction (anti-inflammatory)
How is cortisol produced during the day?
circadian rhythm based on needs
highest in the morning, lowest at night during rest
increases with stress
How is cortisol regulated?
by ACTH of the anterior pituitary
negative feedback effect on ACTH production
What does the zona reticularis produce and what is the main example?
gonadocorticoids
androstenedione
produces in small amounts and their effects are weaker than those produced by the gonads
What does androstenedione do?
can be converted into testosterone and estradiol
What is Addison’s disease and what are the symptoms?
autoimmune destruction of adrenal cortex
underproduction of mineralocoritcoids, glucocoritcoids, and gonadocorticoids
hyperpigmentation of the skin, dehydration, hyperkalemia, metabolic acidosis
What is Cushing’s syndrome?
excessive amounts of corticosteroids are produced
may be iatrogenic - induced by medications, or due to adrenal hyperplasia
hyperglycemia, central obesity, poor wound healing, hypertension, stria, and hirsutism (excessive hair growth)
What type of cells in the adrenal medulla release the hormones, and what are their effects on target cells?
chromaffin cells
produce epinephrine (80%) and norepinephrine (20%)
catecholamines stimulate adrenergic receptors via PiP-Ca2+
fight or flight responses
What are the effects of epinephrine and norepinephrine?
increased heart rate and contractility
increase in blood pressure
peripheral vasoconstriction (mostly due to norepinephrine)
hyperglycemia
effects are brief in comparison to glucocorticoids
How are the hormones of the adrenal medulla regulated?
exclusively neural regulation
stress, low blood sugar, and physical exercise stimulate the sympathetic nervous system
sympathetic stimulation of the adrenal medulla incudes production
What is a tumor on the adrenal medulla called and what are the side effect?
pheochromocytoma
hyperglycemia, tachycardia, and hypertension
Where is the pancreas located?
inferior and posterior to the stomach and medial to the duodenum
What type of gland is the pancreas?
exocrine and endocrine
only focusing on endocrine rn
