Renal Endocrinology

Question 1

Where is erythropoietin (EPO) produced?

Answer 1

In the peritubular cells of the renal cortex.

Question 2

What does erythropoietin do?

Answer 2

Stimulates bone marrow maturation of erythrocytes

Question 3

How do erythropoietin levels change?

Answer 3

Increase: In response to anaemia
Decrease: In response to polcythaemia (increased haemoglobin in blood)

Question 4

Where are the adrenal glands located?

Answer 4

Above the kidneys

Question 5

Give the blood supply to the adrenal glands.

Answer 5

Superior adrenal artery: From inferior phrenic
Middle adrenal artery: From abdominal aorta
Inferior adrenal artery: From renal artery

Question 6

Give the venous drainage of the adrenal glands.

Answer 6

Right adrenal vein drains into the inferior vena cava

Left adrenal vein drains into the left renal vein

Question 7

What is the nerve supply to the adrenal glands?

Answer 7

Splanchnic nerves

Question 8

Name 4 main hormones that the adrenal cortex secretes.

Answer 8

Aldosterone
Cortisol
DHEA
Androstenedione

Question 9

What are the three layers of the adrenal cortex?

Answer 9

Outermost: Zona glomerulosa
Zona fasiculata
Innermost: Zona reticularis

Question 10

What types of hormone does each layer of the adrenal cortex secrete?

Answer 10

Zona glomerulosa: Mineralocorticoids (aldosterone)
Zona fasiculata: Glucocorticoids (cortisol)
Zona reticularis: Androgens (DHEA, androstenedione)

Question 11

Name 2 main hormones that the adrenal medulla secretes.

Answer 11

Adrenaline

Noradrenaline

Question 12

List the effects of adrenaline

Answer 12

Dilates pupils
Increases glycogenolysis
Sweating 
Increases heart rate 
Inhibits insulin release

Question 13

List the features of corticosteroid hormones.

Answer 13

1. Lipid soluble - can pass through cell membrane
2. Bind to specific receptors
3. Alter gene expression
4. Action depends on structure

Question 14

What is the role of cortisol?

Answer 14

STRESS:

1. Increases organic metabolism
2. Vasoconstriction
3. Inhibits nonessential functions e.g. growth

IMMUNITY:

1. Inhibits production of prostaglandins which lead to inflammation
2. Maintains blood pressure
3. Reduces fluid leakage in injured areas

Ultimately prevents immune system over-reacting to minor infections.

DEVELOPMENT:
1. Essential for production of surfactant

Question 15

Give the pathway of cortisol release.

Answer 15

1. Stress is detected and signals are sent to hypothalamus
2. Corticotropin-releasing hormone (CRH) is secreted from hypothalamus
3. CRH travels to the anterior pituitary gland, causing the release of adrenocorticotropic hormone (ACTH)
4. ACTH stimulates cortisol release from the adrenal cortex

Question 16

How much cortisol is actually bioavailable?

Answer 16

Only 5% is free. 90% is bound to corticosteroid-binding globulin, 5% is bound to albumin

Question 17

What effects do adrenaline and noradrenaline have on blood vessels?

Answer 17

Adrenaline: Vasoconstrictor
Noradrenaline: Vasodilator

Question 18

What type of molecule is adrenaline and noradrenaline?

Answer 18

Catecholamine

Question 19

Which receptors have high affinities for noradrenaline and adrenaline respectively?

Answer 19

Noradrenaline: Alpha receptors
Adrenaline: Beta receptors

Question 20

Name three places where kidney stones can get stuck in the ureter/

Answer 20

1. Renal pelvis
2. Opening into bladder (trigone)
3. Over brim of pelvis