2. Adrenal Function

Question 1

What hormones does the adrenal cortex and adrenal medulla produce?

Answer 1

The adrenal cortex produces hormones that controls sex (androgens, estrogens), salt balance in the blood (aldosterone), and sugar balance (cortisol).

The adrenal medulla produces hormones involved in the fight-or-flight response (catecholamines, or adrenaline type hormones such as epinephrine and norepinephrine)

Question 2

What is the anatomy of adrenal gland?

Answer 2

Question 3

The adrenal cortex is divided into 3 zones. What are they and what do they produce?

Answer 3

Question 4

Adrenal cortex hormones: which is hormone is a mineralocorticoid, which hormone is a glucocorticoid, and which are sex hormones

Answer 4

aldosterone - a mineralocorticoid

cortisol - a glucocorticoid

androgens and estrogen - sex hormones

Question 5

What is the function of mineralcorticoids (aldosterone) (3)?

Answer 5

1. Increase urine excretion of K+
2. Increase absorption of Na+
3. Increase retention of H2O

Results in increased blood volume and increase blood pressure

Question 6

What is the function of glucocorticoids (cortisol) (3)?

Answer 6

1. Increase gluconeogensis (formation of glucose from amino acids and fats)
2. Increase blood glucose

Immune system may be suppressed (anti-inflammatory effects)

Question 7

Are mineralocorticoids and glucocorticoids involved in short term stress response or long term stress response?

Answer 7

Aldosterone and Cortisol involved in long term stress response

Question 8

What is the primary target tissue of mineralocorticoids?

Answer 8

Kidney (distal renal tubules)

Question 9

What are the target tissues of glucocorticoids (4)?

Answer 9

1. Adipose tissue (lipolysis)
2. Muscle (protein catabolism)
3. Hepatocytes (gluconeogensis)
4. Immune system (surpressed function)

Question 10

What is DHEA?

Answer 10

The primary androgen produced by the adrenal cortex is dehydroepiandrosterone (DHEA) (and the sulfate metabolite, DHEA-S), which is a precursor to sex hormones such as estradiol and testosterone. Adrenal cortex also produces small amounts estrogen and testosterone

Question 11

What is required to make adrenal cortex hormones (2)?

Answer 11

Free cholesterol (substrate) and pathway enzymes in each zone.

Question 12

In the renin/angiotensin system, which hormone is responsible for the release of aldosterone from the adrenal cortex and vasocontriction of the arterioles?

Answer 12

Angiotensin II

Question 13

In the renin/angiotensin system, what triggers/starts the system (stimuli)?

Answer 13

Dehydration, Na+ deficiency, or hemorrhage, resulting in decrease in blood volume and blood pressure

Question 14

In the renin/angiotensin system, decrease in blood volume and blood pressure triggers kidney to produce ________, which activates __________ produced by the liver and makes __________. This is then activated by __________ to make ____________. This hormone causes vasocontriction of arterioles that ___________ blood pressure. This hormone also stimulates adrenal cortex to produce ____________, which increases Na __________ and K _________ to _________ blood volume. This will also __________ blood pressure.

Answer 14

In the renin/angiotensin system, decrease in blood volume and blood pressure triggers kidney to produce (renin), which activates (angiotensinogen) produced by the liver and makes (angiotensin I). This is then activated by (ACE = angiotensin converting enzyme) to make (angiotensin II). This hormone causes vasocontriction of arterioles that (increase) blood pressure. This hormone also stimulates adrenal cortex to produce (aldosterone) which increases Na (absorption) and K (secretion) to (increase) blood volume. This will also (increase) blood pressure.

Question 15

What is hyperadrenalism?

Answer 15

Excess production of hormones of adrenal cortez

Question 16

What are the two conditions that fall under hyperadrenalism?

Answer 16

1. Hyperaldosteronism
2. Cushings syndrome
3. Congenital Adrenal Hyperplasia

Question 17

What is hyperaldosteronism? What are the two main causes?

Answer 17

Excess aldosterone production.

1. Conn’s syndrome (primary hyperaldosteronism) - due to aldosterone-secreting adrenal adenoma or adrenal hyperplasia
2. Renin secreting tumor - excess renin leads to elevated aldosterone levels

Question 18

What are signs of hyperaldosteronism (3)

Answer 18

Hypertension, hyperatremia (High Na) hypokalemia (low K)

Question 19

What is cushings syndrome? What is the most common cause?

Answer 19

Excess production of cortisol

Most common cause: ACTH secreting pituitary adenona

Need to determine ACTH-dependent or ACTH-independent hypercortisolism

Question 20

Cushings syndrome involves excess cortisol, but it can result in a decrease in ___________ and __________

Answer 20

Aldosterone (hypoaldosteronism) and renin production

Question 21

What is congenital adrenal hyperplasia?

Answer 21

Genetic disorder causing deficiency in enzymes in synthetic pathways that lead to cortisol and aldosterone productions

People with CAH cannot properly make cortisol and in some cases, are unable to produce aldosterone. They also produce too much of some androgens.

Question 22

What is the three criteria to diagnose primary aldosteronism?

Answer 22

1. Plasma aldo (PA)/plasma renin activity>25 (more aldo than renin ratio)
2. Low plasma renin that fails to increase with volume depletion
3. High aldo that fails to decrease with saline/angiotensin inhibition