Endocrine Disorders

Question 1

What does thyroid hormone (produced from the thyroid gland) consist of?

Answer 1

T3-tri-iodo-thyronine
T4- thyroxine

T4 is most commonly produced by T3 is the active form
activation usually occurs in the peripheral tissues

Question 2

What effects can hypo/hyperthyroidism have on levels of TSH and T3/T4? (using HPG axis) watch video in lecture for explanation

Answer 2

Primary hypothyroidism- T3/T4 is low, TSH is high (no negative feedback to tell TSH production to regulate)
secondary hypothyroidism- T3/T4 is low, TSH is low
primary hyperthyroidism- T3/T4 is high, TSH is low
secondary hyperthyroidism - T3/T4 is high, TSH is high

Question 3

What do the adrenal glands sit on top of?

Answer 3

The kidneys

Question 4

What 3 sections is the cortex split into and what is secreted from each section?

Answer 4

zona glomerulosa- secretes mineralocorticoids ie aldosterone
zona fasciculata- secretes glucocorticoids ie cortisol
zona reticularis- secretes adrenal androgens

Question 5

What are some examples of disorders of adrenocortical function?

Answer 5

excess cortisol- Cushing’s syndrome
excess aldosterone- Conn’s syndrome
hypercortisolism
lack of aldosterone and cortisol- Addisons

Question 6

What is aldosterone secretion activated/regulated by?

Answer 6

1. RAAS
2. Increased Plasma potassium conc

RAAS is activated by:
1.reduced renal perfusion
2. increased sympathetic activity
both re interpreted as a fall in blood volume

excess aldosterone = leads to hypertension