adrenal gland and steroid hormones

Question 1

why does cortisol levels peak in first few hours of waking up?

Answer 1

1. maintain blood glucose levels
2. stimulate appetite
3. prepare for potential stressful situations

Question 2

During fasting, cortisol increases blood glucose levels, in part by regulating which processes in muscle?

Answer 2

Stimulating protein catabolism and reducing glucose uptake

Question 3

Cortisol-induced protein catabolism and lipolysis provide the raw materials for which process in the liver

Answer 3

gluconeogenesis

Question 4

What “permissive” effects does cortisol have on the cardiovascular system?

Answer 4

Increases adrenergic receptor expression, enabling catecholamines to increase cardiac output and blood pressure

Question 5

As a stress hormone, cortisol plays an important role in maintaining immune homeostasis by:

Answer 5

1. Repressing the production of pro-inflammatory cytokines and inflammatory mediators, such as prostaglandins
2. Suppress growth and function of key immune cells like lymphocytes
3. Stabilises lysosomal membranes in damaged cells, preventing the release of their proteolytic contents
4. Decreases capillary permeability in injured areas

Question 6

Elevated levels of cortisol suppress which two physiological processes with high anabolic cost?

Answer 6

reproduction and growth

Question 7

What are some of the symptoms of Addison’s disease?

Answer 7

Anorexia
Depression
Distribution of hair
Irritability
Skin pigmentation (increased ACTH → bronze skin pigmentation)
Orthostatic hypotension
Na+ craving (hypnatremia)
Irregular periods
Abdominal pain
Nausea/vomiting

Weakness, fatigue
Loss of appetite, loss of weight
Hypoglycaemia

Question 8

What is the most common cause of Cushing’s syndrome today?

Answer 8

Pharmacological use of exogenous corticosteroids

Question 9

What is the rate-limiting step in steroidogenesis?

Answer 9

transport of cholesterol into mitochondria via Steroidogenic acute regulatory protein (and conversion to pregnenolone)

Question 10

what is Conn’s syndrome?

Answer 10

primary hyperaldosteronism

Question 11

what are some symptoms/signs in Cushing’s syndrome?

Answer 11

1. Central obesity, moon face, buffalo hump
2. ulcers
3. skin changes (hyperpigmentation, striae)
4. hypertension, hyperandrogenism (hair growth, acne, amenorrhoea)
5. impaired wound healing
6. neuromuscular weakness
7. glycosuria
8. osteoporosis
9. immunosuppresion
10. depression, psychosis

Question 12

what is common enzyme deficiency in congenital adrenal hyperplasia?

Answer 12

21-hydroxylase deficiency

Question 13

what are classical symptoms of pheochromocytoma (tumour of adrenal gland)?

Answer 13

1. restlessness
2. headaches
3. palpitations
4. elevated blood pressure

Question 14

does cortisol upregulate or downregulate GH-IGF-1 axis?

Answer 14

downregulate

Question 15

what are the actions of cortisol?

Answer 15

1. increase glucose stores
2. increase adrenergic receptor expression (permissive effects on catecholamines)
3. immune suppression
4. decrease reproduction function (inhibit GH, IGF-1)
5. increase bone resorption

Question 16

what causes Cushing’s disease?

Answer 16

ACTH-secreting pituitary tumour

Question 17

what findings would be seen in untreated congenital adrenal hyperplasia?
a. adrenal glands of normal size
b. decreased levels of ACTH and cortisol
c. elevated levels of ACTH and androgens
d. normal female genitalia
e. suppressed ACTH levels

Answer 17

c. elevated levels of ACTH and androgens