Adrenal glands

Question 1

where do the adrenal glands sit

Answer 1

one sits on top of each of the kidneys

Question 2

what are the different parts of the adrenal gland(from top to bottom)

Answer 2

capsule, cortex and medulla

Question 3

what different parts is the adrenal cortex split up into

Answer 3

zona glomerulosa, zona fasciculata, zona reticularis

Question 4

what type of hormone is the zona glomerulosa section of the adrenal cortex responsible for secreting

Answer 4

mineralocorticoids(eg aldosterone)

Question 5

what type of hormone is the zona fasciculata section of the adrenal cortex responsible for secreting

Answer 5

glucocorticoids(eg cortisol, corticosterone)

Question 6

what type of hormone is the zona reticularis section of the adrenal cortex responsible for secreting

Answer 6

adrenal androgens(eg DHEA, androstenedione)

Question 7

what type of cells are found in the adrenal medulla and what type of hormones do they produce

Answer 7

chromaffin cells, produce catecholamines(eg adrenaline, noradrenaline)

Question 8

what is the starting point/signal for production of hormones by the different parts of the adrenal cortex

Answer 8

cholesterol

Question 9

what is the rate limiting step in the biosynthesis of hormones by the adrenal cortex

Answer 9

uptake of cholesterol and conversion to pregnenolone(is then converted to many compound eventually hormones secreted)

Question 10

what is cortisol and androgen production regulated by

Answer 10

hormones produced by hypothalamus and anterior pituitary

HPA axis, HPA = hypothalamic pituitary adrenal

Question 11

what is aldosterone production regulated by

Answer 11

RAAS and plasma potassium

Question 12

describe the HPA axis

Answer 12

hypothalamus secretes CRH(levels depend on illness, stress, time of day), acts on pituitary to secrete ACTH, acts on adrenal cortex to secrete cortisol

Question 13

what are CRH and ACTH

Answer 13

CRH = corticotropin releasing hormone
ACTH = adrenocorticotropic hormone

Question 14

what type of loop is seen in the HPA axis

Answer 14

negative feedback loop, high levels of cortisol inhibits CRH and ACTH release

Question 15

describe the Renin-angiotensin aldosterone system(RAAS) regulation of aldosterone

Answer 15

activated in response to decreased BP, leads to production Ang II which directly(vasoconstriction0 increases BP and indirectly by stimulating aldosterone release from adrenal cortex(salt retention)

Question 16

what are the 3 principal clinical uses of corticosteroids

Answer 16

suppress inflammation, suppress immune system, replacement treatment

Question 17

where are mineralocorticoid receptors(MR) most prominently placed

Answer 17

mainly kidneys, also salivary glands, gut, sweat glands

Question 18

what affects can aldosterone when acting on mineralocorticoid receptors(MR)

Answer 18

regulate Na/K balance(K+/H+ excretion and increase Na reabsorption), BP regulation, regulation of extracellular volume