Neuroendocrine system

The Neuroendocrine system is a system that is the overlapping three systems found both in the nervous system and the endocrine system, primarily responsible for neural modulation of endocrine function stationed near the brain.

It consists of the hypothalamus and the anterior and posterior areas of the pituitary gland.

Anatomy
The hypothalamus is inferior to the thalamus and is connected to the fleshy outgrowth of the brain known as the pituitary gland by a stalk of tissue known as the hypophysis, and populated with axon tracts that electrochemically allow communication between the hypothalamus and selective regions of the pituitary gland.

Male reproduction
The hypothalamus secretes GnRH, which stimulates the anterior lobe of the pituitary gland to secrete FSH and LH, which enter the bloodstream to influence activities in the testes.

Progenitor restricted stem cells, spermatogonads, in the tests semiconservatively proliferate and differentiate to form dedicated sperm progenitors. Increased levels of FSH increase the number of spermatogonads that become dedicated sperm progenitors.

Increased levels of LH influences the secretory cell population in the testes, Leydig cells, to secret testosterone to accelerate the rate of sperm development.