steroids of the adrenal cortex

Question 1

What are the three steroids of the adrenal cortex

Answer 1

glucocorticoids - principally cortisol; mineralorticoids - aldosterone; androgens

Question 2

disease associated with excess cortisol

Answer 2

Cushing’s

Question 3

disease associated with adrenal insufficiency (primarily cortisol)

Answer 3

Addison’s

Question 4

blood flow in the adrenal glands

Answer 4

blood flows from outer cortex to inner medulla

Question 5

what are does having layer specific enzymes mean

Answer 5

steroid synthesis in one layer can inhibit different enzymes in subsequent layers

Question 6

synthesis of aldosterone in the adrenal cortex

Answer 6

MITOCHONDRIA: cholesterol > pregnenolone
SER: pregnenolone > progesterone > deoxycorticosterone
MITOCHONDRIA: deoxycorticosterone > corticosterone > aldosterone

Question 7

cortisol synthesis in the adrenal cortex

Answer 7

nah

Question 8

action of mineralcorticoids

Answer 8

salt and water balance

Question 9

action of glucocorticoids

Answer 9

metabolism and immune function (stress increases release)

Question 10

control of aldosterone secretion

Answer 10

angiotensin (liver) + renin > angiotensin I + ACE > angiotensin II > ATI receptors, increases aldosterone secretion in adrenal cortex

Question 11

other functions of angiotensin II

Answer 11

increase thirst in brain, vasoconstriction of blood vessels

Question 12

Cortisol and aldosterone have similar affinity for the aldosterone receptor, and circulating [cortisol] is much higher than aldo.; so why doesn’t cortisol stimulate salt and water retention?

Answer 12

• cortisol rapidly metabolised to inactive cortisone in the kidney via 11beta-hydroxysteroid dehydrogenase type 2

Question 13

Functions of glucocorticoids

Answer 13

(glucose sparing) - proteolysis, gluconeogenesis (mainly from AA), lipolysis
OVERAL
maintenance of BG - essential during fasting

Question 14

CV functions of glucocorticoids

Answer 14

vascular integrity; cortisol deficiency = inappropriate vasodilation, cortisol excess = hypertension

Question 15

immune function of glucocorticoids

Answer 15

anti inflammatory - immunosuppressive

Question 16

What are the two major isoforms of glucocorticoid receptor (GR)

Answer 16

alpha and beta

Question 17

What gives rise to the two forms of GR

Answer 17

alternate splicing of 9th exon

Question 18

what does CRH stand for

Answer 18

corticotropin-releasing hormone

Question 19

what does ACTH stand for

Answer 19

adrenocorticotropic hormone/corticotropin

Question 20

ACTH is synthesized from which prohormone

Answer 20

opiomelanocortin

Question 21

Which group of receptors is the ACTH receptor in

Answer 21

melanocortin

Question 22

What can be cause by excess circulating ACTH

Answer 22

skin pigmentation

Question 23

What is addisons disease

Answer 23

primary adrenal insufficiency; low circulating adrenal steroids, high ACTH

Question 24

How can addison’s cause skin pigmentation

Answer 24

ACTH on melanocortin receptors

Question 25

How can addison's cause hypotension

Answer 25

loss of aldosterone

Question 26

Usual cause of addison's

Answer 26

autoimmune

Question 27

Common clinical features of addison's disease

Answer 27

weakness, weight loss, pigmentation, postural hypotension, anorexia, nausea, abdominal pain

Question 28

uncommon clinical features of addison's disease

Answer 28

vitiligo, salt craving, hypoglycaemia in adults, aches and pains

Question 29

What is cushings syndrome

Answer 29

PRIMARY: excess exogenous glucocorticoid,, low ACTH | SECONDARY ^ with endogenous increased ACTH secretion, typically due to pituitary adenoma

Question 30

symptoms of cushings

Answer 30

centripetal obesity, slim arms and legs, bruising, hirsuitism

Question 31

cushing's diagnosis

Answer 31

24h cortisol, cortisol/ACTH 9am & midnight, dexamethasone suppression test

Question 32

what is dexamethazone

Answer 32

exogenous steroid

Question 33

what do low doses of dexamethazone do ACTH secretion

Answer 33

suppress secretion via -ve feedback BUT suppression fails in cushing's

Question 34

what do high doses of dexamethazone do ACTH secretion

Answer 34

suppress it, even in cushings

Question 35

What is suggested if ACTH secretion is not suppressed with a high OR low dose of dexamethazone

Answer 35

ectopic source of ACTH eg tumour elsewhere