11th April 2024

Physiology

The normal functioning of the Hypothalamic-Pituitary-Adrenal axis (HPA axis) consists of a series of negative feedback loops that regulate the release of hormones from endocrine glands around the body. The HPA regulation of reproductive hormone release involves the secretion of GnRH from the hypothalamus. GnRH acts on anterior pituitary gonadotrophs to release LH and FSH. LH and FSH then act on cells in the gonads to produce sex hormones, predominantly testosterone in males and oestrogen in females. Testosterone and oestrogen have an inhibitory effect on the release of GnRH from the hypothalamus and FSH and LH from the Anterior Pituitary.