Adrenal Gland Flashcards
what are the three zones of the adrenal cortex
zona glomerulosa, zona fasciculata, and zona reticularis
which zone(s) of the adrenal gland is/are controlled by the hypothalamus and pituitary
fasciculata and reticularis
which zone(s) of the adrenal gland is/are NOT controlled by the hypothalamus
zona glomerulosa (and the medulla, although it is not technically a zone)
what zone secretes glucocorticoids (cortisol and corticosterone)
zona fasciculata
what zone secretes the gonadal steroids (estrogen, progesterone, androgens)
zona reticularis
what secretes epineprhine and norepineprhrine?
the adrenal medulla
what zone secretes aldosterone
zona glomerulosa
what is the mechanism of action of aldosterone
it increases sodium retention/reabsorption, and inreases calcium, H, and K excretion (hypokalemia)
what induces aldosterone secretion
hyponatremia, hyperkaliemia, low extracellular fluid volume
regulation of glucocorticoid synthesis (sorry :( )
ACTH -> adrenal cortex -> cholesterol -> mitochondria -> pregnenolone synthesis -> SER -> 11-Deoxycortisol + 11- Deoxycorticosterone -> mitrochondria -> cortisol and corticosterone (glucocorticoids)
effects of excess glucocorticoids on carbohydrates
- causes hyperglycemia due to decreased affinity of insulin receptors to insulin
- promotes uptake of glu
- increases glycogen storage in liver (hepatomegaly)
effects of excess glucocorticoids on proteins
- reduces muscle mass
- thin and friable skin
- osteoporosis due to loss of bone matric proteins and calcium
effects of excess glucocorticoids on lipids
- fat mobilized to neck, shoulder and abdomen
- supraorbital fat pad
- lipolysis /hypercholesterolemia
effects of excess glucocorticoids on minerals
Na retention and K excretion (hypokalemia, Na:K ratio > 40:1)
Decreased Ca absorption
effects of excess glucocorticoids on water metabolism
increase excretion of water by interfering with ADH release (polyuria and polydipsia)
how does excess glucocorticoids cause metabolic alkalosis
increase loss of H ions