Growth hormone

Question 1

Secreted by

Answer 1

somatotroph cells of the anterior lobe of the pituitary gland

Question 2

Functions of growth hormone

Answer 2

Postnatal growth and development
Numerous actions on protein, carbohydrate and fat metabolism (including increasing lipolysis and gluconeogenesis)

Question 3

Mechanism of action of growth hormone

Answer 3

• acts on a transmembrane receptor
• leads to receptor dimerization
• acts directly on tissues and also indirectly via insulin-like growth factor 1 (IGF-1), primarily secreted by the liver

Question 4

What factors increase secretion of growth hormone

Answer 4

growth hormone releasing hormone (GHRH): released in pulses by the hypothalamus
fasting
exercise
sleep (particularly delta sleep)

Question 5

What decreases growth hormone secretion?

Answer 5

glucose
somatostatin (itself increased by somatomedins, circulating insulin-like growth factors, IGF-1 and IGF-2)

Question 6

Condition of excess growth hormone

Answer 6

Acromegaly

Question 7

What occurs in conditions where there is a lack of growth hormone?

Answer 7

Short stature