Lecture 30

Question 1

How is growth hormone release controlled?

Answer 1

GHRH has a positive effect by binding to GNRHR, GHIH and somatostatin have a negative impact upon the release of growth hormone (inhibiting the release).

Question 2

How do plasma nutrient concentrations impact upon growth hormone?

Answer 2

Low plasma nutrient concentrations cause hypoglycemia (a decrease in plasma fatty and amino acids) resulting in upward regulation of growth hormone.

Question 3

What is the effect of malnutrition and fasting upon growth hormone?

Answer 3

Upward regulation of growth hormone

Question 4

When in the day are growth hormone concentrations generally the greatest?

Answer 4

growth hormone concentrations are generally the highest at night

Question 5

How does Ghrelin impact upon the secretion of growth hormone?

Answer 5

Synthesised in the stomach and in other tissues, the hormone of hunger is produced when we are starving. Binds to GHSR inducing GH synthesis and release from the anterior pituitary.

Question 6

How does GH secretion vary with age?

Answer 6

Decreases as we age

Question 7

FIll in the following blanks in the table below:

Answer 7

1. Liver production of IGF’s
2. Insulin antagonist
3. Cartiladge formation and skeletal growth
4. Protein synthesis, Cell growth and proliferation
5. Lipolysis
6. Increase blood glucose