Adrenal Cortex

Question 1

Consequences of obsence of the mineralocorticoid, aldosterone (zona glomerulosa)

Answer 1

• loss Na+
• decrease volume ECF
• low blood pressure
• circulatory shock
• death

Question 2

Consequences of absence of glucocorticoid, cortisol (zona fasciculata, zona reticularis)

Answer 2

• circulatory failure

- inability to mobilize energy sources from glycogen or fat

Question 3

Why absence of cortisol results in circulatory failure?

Answer 3

Cathecolamines need cortisol to work - exert vasoconstriction

Question 4

Implications of inability to mobilize energy resources from glycogen and fat in absence of cortisol context

Answer 4

• Normal conditions - not life-threatening

- Stress - fasting - fatal hypoglycemia

Question 5

If there is a problem with anterior pituituary secretion, whicht adrenal cortex hormone is not affected on its production? What stimulus controls it?

Answer 5

• Aldosterone

- Angiontesin II, k+

Question 6

Only negative feedback for ACTH on pituitary

Answer 6

Cortisol

*Other adrenals hormones don’t make (-) feedback

Question 7

Index of all androgens, adrenal and testicular? index of androgen production by the adrenals?

Answer 7

• Urinary 17-ketosteroids

- Sulfated form of 17-ketosteroids

Question 8

What is the weak mineralocorticoid that can keep you alive without hypothetical 11 B-OH deficiency?

Answer 8

11-Deoxycorticosterone

Question 9

What mechanisms does cortisol use to raise blood glucose?

Answer 9

• counteracts insulin’s actions in most tissues
• gluconeogenesis
• permissive actions for glucagon and cathecolamines

Question 10

What change in the body you may see when excessive secretion of ACTH (primary adrenal insufficiency as example)? Why?

Answer 10

• darkening of the skin

- alfa-MSH sequence within ACTH, B-MSH activity of B-lipoprotein

Question 11

How does the aldosterone mediate the secretion of K+ at principal cell in collecting duct?

Answer 11

Reabsorption of Na ▶️ (-) luminal potential ▶️ K+ excretion

Question 12

About acid-base estate, what can the excess and insufficient of aldosterone produce and why?

Answer 12

• excess: alkalosis

- deficiency: acidosis (type IV RTA)

Question 13

Why a volume-depleted states tend to produce alkalosis?

Answer 13

⬆️ aldosterone (compensate volume ⬇️) ▶️ ⬆️ excretion H+ and ⬆️ plasma HCO3

Question 14

Hypercortisolism due to an adenoma of the anterior pituitary (microadenoma)

Answer 14

Cushing disease

*cushing syndrome is hypercortisolism regardless origin (including chronic corticoid therapy)

Question 15

In what cases could you have false positive of the 1-mg overnight dexamethasone suppression test?

Answer 15

Depression or alcoholism

Question 16

If you are sure about a hypercortisolism, and got a high ACTH level, how can you distinguish pituitary vs ectopic source?

Answer 16

High-dose dexamethasone suppression test

• pituitary source: cortisol decreases
• ectopic ACTH (adrenal tumor also): cortisol not suppressed

Question 17

What test do you use to diagnose adrenal insufficiency (Addison disease)?

Answer 17

ACTH stimulation test

Question 18

Clinical presentation of adrenal adenoma, what is the disease?

Answer 18

Unilateral, only cortisol secretes, ⬇️ adrenal androgen and deoxycorticosterone (no hirsutism)
- primary hypercortisolism

Question 19

What do you suspect if in context of primary hypercortisolism there is an androgen and mineralocorticoid excess?

Answer 19

Adrenal Carcinoma

Question 20

Most common cause of secondary hypocortisolism

Answer 20

Sudden withdrawal of exogenous glucocorticoid therapy

Question 21

What test can you make if suspect hypocortisolism (adrenal insufficiency) but the ACTH stimulation test was relatively normal?

Answer 21

Insulin infusion

Question 22

How do you distinguish a secondary from primary (Addison’s) adrenal insufficiency?

Answer 22

ACTH levels

• ⬆️: primary (Addison’s disease)
• ⬇️: secondary

Question 23

Diagnosis if cortisol not suppressed with 1 mg overnight dexamethasone test and high dose dexamethasone ACTH suppressed

Answer 23

Secondary hypercortisolism - pituitary source (Cushing disease)

Question 24

How do you distinguish a primary vs secondary hyperaldosteronism?

Answer 24

• primary (conn’s syndrome): ⬇️ renin, ⬆️ aldosterone

- secondary: ⬆️ renin, ⬆️ aldosterone

Question 25

Difference between 21B OH and 11B OH deficiency

Answer 25

• 21B OH deficiency: hyperkalemia, ⬆️ renin

- 11B OH deficiency: hypokalemia, ⬇️ renin, Hypertension