Adrenal Glands

Question 1

What are the 3 zones of the adrenal cortex from outer to inner layers?

Answer 1

Zona glomerulosa
Zona fasciculata
Zona reticularis

Question 2

What hormones are produced by the zona glomerulosa?

Answer 2

Mineralocorticoids e.g., Aldosterone

Question 3

What hormones are produced by the zona fasciculata?

Answer 3

Glucocorticoids e.g., cortisol, corticosterone

Question 4

What hormones are produced by the zona reticularis?

Answer 4

Adrenal androgens e.g., DHEA, testosterone

Question 5

What cells make up the adrenal medulla?

Answer 5

Chromaffin cells

Question 6

What hormones are produced by the adrenal medulla?

Answer 6

Catecholamines e.g., adrenaline, noradrenaline

Question 7

Corticosteroids formed in the adrenal cortex are all derived from a ? backbone

Answer 7

Cholesterol

Different enzymes in each zone lead to production of different hormones

Question 8

Name the main hormones produced by each zone of the adrenal cortex

Answer 8

Zona glomerulosa -> aldosterone

Zona fasciculata -> cortisol

Zona reticularis -> adrenal androgens

Question 9

How is cortisol and androgen production regulated?

Answer 9

The HPA axis

hypothalamic-pituitary-adrenal axis

Question 10

How is aldosterone production regulated?

Answer 10

The renin-angiotensin-aldosterone system (RAAS) and plasma K+

(independent of the HPA axis)

Question 11

Describe the hypothalamic-pituitary-adrenal axis

Answer 11

• Hypothalamus releases CRH (cortisol releasing hormone) in response to illness, stress or depending on the time of day (diurnal pattern)
• CRH stimulates the anterior pituitary to secrete ACTH (adrenocorticotropic hormone)
• ACTH stimulates the adrenal cortex to produce cortisol

Question 12

Describe -ve feedback in relation to the HPA axis

Answer 12

Excess cortisol can go back to inhibit the hypothalamus and anterior pituitary from secreting CRH and ACTH respectively

Question 13

Describe how RAAS regulates aldosterone production

Answer 13

• Kidneys detect reduced BP
• Renin concerts ang into ang I
• ACE converts ang I into ang II
• Ang II causes the adrenal cortex to produce more aldosterone

Question 14

Why does the RAAS system result in increased aldosterone?

Answer 14

Increased aldosterone results in salt retention in the kidneys, leading to an increase in BP

Question 15

What type of receptor to corticosteroids bind to?

Answer 15

Nuclear receptors

Question 16

What are the 6 classes of steroid receptor?

Answer 16

• Glucocorticoid
• Mineralocorticoid
• Progestin
• Oestrogen
• Androgen
• Vitamin D

Question 17

List 3 clinical uses of corticosteroids e.g., cortisol

Answer 17

• Anti-inflammatory e.g., asthma, anaphylaxis, Crohns, UC, rheumatoid arthritis
• Immunosuppression e.g., malignancy
• Replacement treatment if unable to produce enough endogenous hormone

Question 18

Aldosterone acts on mineralocorticoid receptors (MR) in the… (4)

Answer 18

Kidneys
Salivary glands
Gut
Sweat glands

Question 19

What are the 2 main roles of aldosterone in the body?

Answer 19

• BP regulation (increased aldosterone increases BP)

- Na+/K+ balance (Na+ is reabsorbed in exchange for K+ excretion)