adrenal hormones

Question 1

Which hormone released from they hypothalamus regulates release of ACTH from the anterior pituitary?

Answer 1

Corticotropin releasing hormone (CRH)

Question 2

Which glands does ACTH act on?

Answer 2

The adrenal glands

Question 3

Which major hormones are secreted by the adrenal cortex?

Answer 3

mineralcorticoids (aldosterone), glucocortoids (cortisol),oestrogen, androgens

Question 4

Which major hormones are secreted by the adrenal medulla?

Answer 4

Adrenaline, noradrenaline

Question 5

What are the 3 layers of the adrenal cortex?

Answer 5

Zona glomerulosa, zona fasciculata, zona reticularis (superficial to deep)

Question 6

Which zone of the adrenal cortex produces cortisol?

Answer 6

Zona fasciculata

Question 7

What is the process of production of cortisol?

Answer 7

1. ACTH binds to the Zona fasciculata in the adrenal cortex.
2. Cholesterol is transported into cell mitochodnria and is converted to pregnenolone (steroid hormone precursor)
3. Pregnenolone is converted to cortisol

Question 8

What are the metabolic functions of cortisol?

Answer 8

Increases adipose breakdown to release fatty acids, increases muscle protein breakdown, increases gluconeogenesis and glycogenolysis in the liver increase blood glucose levels.

Question 9

What are the non-metabolic effects of cortisol?

Answer 9

Increases blood pressure, suppresses the immune system appropriately

Question 10

What is the pattern of cortisol secretion?

Answer 10

Secretion is cyclical, with levels highest in the morning. There is also pulsatile release in response to stress.

Question 11

What are the negative feedback loops associated with cortisol?

Answer 11

cortisol has negative feedback to the hypothalamus and the anterior pituitary

Question 12

What are the causes of Cushing’s Syndrome?

Answer 12

Cushing’s disease (ACTH secreting pituitary adenoma), Ectopic ACTH secreting tumor, Adrenal adenoma/carcinoma secreting cortisol. adrenal hyperplasia, excessive corticosteroid use

Question 13

What type of tumor is most likely to become an ectopic ACTH secreting lesion?

Answer 13

Small cell bronchus carcinoma

Question 14

What are the symptoms of Cushing’s syndrome?

Answer 14

Weight gain in face/upper back/abdomen, thin skin, striae, muscle weakness/wasting, fatigue, hypertension, hyperglycaemia, osteoporosis, depression/anxiety, irregular menstruation, hirsutism

Question 15

What biochemical abnormalities are common in Cushing’s syndrome?

Answer 15

hypokalemia, hypernatremia, alkalosis

Question 16

What are the results of a 24 urinary free cortisol test in Cushing’s syndrome?

Answer 16

Would expect high levels

Question 17

What are the results of a low-dose dexamethasone suppression test in Cushing’s syndrome?

Answer 17

Cortisol levels usually will remain elevated, regardless of the cause of the Cushing’s syndrome

Question 18

What are the results of a high-dose dexamethasone suppression test in Cushing’s syndrome?

Answer 18

Pituitary ACTH tumors will show cortisol suppression,
Ectopic ACTH tumors/adrenal tumors will not show cortisol supression at high doses as they are not affected by negative feedback.

Question 19

What are the levels of plasma ACTH in Cushing’s syndrome?

Answer 19

High ACTH suggests pituitary/ectopic tumor secretion, while low ACTH suggest adrenal tumor

Question 20

What are the non-pharmacological treatments for Cushing’s syndrome?

Answer 20

Surgical/radiation tumor removal from pituitary/ectopic/adrenals

Question 21

What are the pharmacological treatments for Cushing’s syndrome?

Answer 21

Glucocorticoid receptor antagonists (mifepristone), steroidogenesis receptor antagonists

Question 22

What are the causes of Addison’s disease?

Answer 22

Autoimmune adrenalitis, adrenal infecton (TB, HIV, fungal), adrenal caricinoma, congential adrenal hyperplasia

Question 23

What is congenital adrenal hyperplasia?

Answer 23

A genetic condition that impairs the production of many adrenal hormones via an enzyme deficiency.

Question 24

What are the symptoms of Addison’s disease?

Answer 24

Fatigue, weakness, weight loss, skin hyperpigmentation, hypotension, syncope, hypoglycaemia, nausea, abdominal pain, depression

Question 25

Why does Addison’s disease cause skin hyperpigmentation?

Answer 25

Addison’s disease causes excess ACTH production. A breakdown product of ACTH is Melanocyte Stimulating Hormone, which can cause melanocytes to secrete excess melanin

Question 26

What is an Addisionian Crisis?

Answer 26

A severe, acute adrenal insufficiency, leading to severe dehydration, hypotension, hypoglycaemia

Question 27

What are the investigations used to diagnose Addison’s disease?

Answer 27

Bloods will show low cortisol and high ACTH. Electrolytes (Na, K) will be low and renin will be high due to aldosterone deficiency, 21-hydroxylase antibody test will be positive if there is an autoimmune cause. ACTH stimulation test will not show a rise in cortisol.

Question 28

What are the pharmacological treatments for Addison’s disease?

Answer 28

Glucocorticoids (oral hydrocortisone), with increased dosing during illness,
Mineralcorticoids (to replace aldosterone)

Question 29

What are the symptoms of (partial) congenital adrenal hyperplasia?

Answer 29

Usually cortisol will be normal but androgens will be increased:
females - clitoromegaly, ambiguous genitalia, ameorrhoea,
males - early pubic hair, precocious puberty

Question 30

What enzyme deficiency most commonly causes congenital adrenal hyperplasia?

Answer 30

21-hydroxylase

Question 31

Why does congenital adrenal hyperplasia cause an increase in androgen production?

Answer 31

The deficient enzyme impairs cortisol production, which triggers ACTH secretion. The androgen pathway is usually intact, so ACTH will cause an increase in androgen release

Question 32

What are the diagnostic markers for congenital adrenal hyperplasia?

Answer 32

Raised ACTH, low/normal cortisol, Increased 17-OH progesterone (precursor for 21-hydroxylase), raised plasma DHEA (androgen)

Question 33

What are the pharmacological interventions for congenital adrenal hyperplasia?

Answer 33

Hydrocortisone, spironolactone (mineralocorticoid antagonist)