HPG Axis

Question 1

HPG Axis - pulsatile secretion

Answer 1

Normal GnRH secretion is pulsatile (gonadotrophin releasing hormone)
Continuous non pulsatile administration of GnRH causes decreased LH/FSH secretion

Question 2

HPG Axis - Hypogonadism - what is it?

Primary Hypogonadism causes In women and men

Answer 2

Hypogonadism:
Decreased oestrogen in a woman
Decreased testosterone in a man

Primary Hypogonadism:
High LH/FSH
Low E2/Testo

Causes:
Men - eg infection/trauma/cancer of testes
Women - Menopause

Question 3

Secondary Hypogonadism causes

Effects on hormone levels

Answer 3

Secondary Hypogonadism causes:
Pituitary tumour, high prolactin

Low (or normal) LH/FSH
Low E2/testo

Question 4

HPG Axis - Menopause

Hormone levels?
FSH/LH/E2/Inhibin

Answer 4

Primary Hypogonadism
Low E2
High LH/FSH
Low inhibin