Adrenal physiology

Question 1

Where are the adrenal glands located? [2]

Answer 1

above the kidneys / retroperitoneally

Question 2

What are the adrenal glands composed of? [5]

Answer 2

1. adrenal cortex - zona glomerulosa / zona fasciculata / zona reticularis
2. adrenal medulla

Question 3

What laters of the adrenal cortex produce what? [3]

Answer 3

1. zona glomerulosa - mineralocorticoids e.g. aldosterone
2. zona fasciculata - glucocorticoids e.g. cortisol
3. zona reticularis - androgens (sex hormones)

Question 4

What is the function of aldosterone? [4]

Answer 4

important for maintaining salt balance / and blood pressure maintenance

acts on the distal convoluted tubule and collecting ducts / increases Na+ reabsorption and K+ excretion

Question 5

What is the zona glomerulosa controlled by? [2]

Answer 5

responds to renin release by juxtaglomerular cells of afferent arterioles in the kidney / so not affected by pathology of the hypothalamus or pituitary

Question 6

What is the function of cortisol? [5]

Answer 6

1. carbohydrate, protein and lipid metabolism
2. facilitates body’s response to stress
3. affects reactivity of blood vessels to adrenaline and noradrenaline so helps maintain normal blood pressure
4. reduces inflammatory response to injury/infection
5. suppresses the immune system

Question 7

What are some examples of androgens? [2]

Answer 7

1. DHEA - dehydroepiandrosterone

2. androstenedione

Question 8

What is cortisol and androgen production controlled by? [3]

Answer 8

CRH from the hypothalamus / stimulates the anterior pituitary to secrete ACTH / which in turn stimulates the adrenal cortex to produce cortisol and androgens

Question 9

What does the adrenal medulla secrete? [2]

Answer 9

catecholamines / such as adrenaline and noradrenaline

Question 10

What is the medulla controlled by? [2]

Answer 10

sympathetic control / normal catecholamine synthesis dependent on high local cortisol levels