How does the hypothalamus control hormone release from the anterior pituitary gland?

The hypothalamus controls the release of hormones from the anterior pituitary gland through a specialized vascular connection known as the hypophyseal-portal circulation.123

The process functions as follows:

• Neurohormone Production: Specialized neurosecretory cells within the hypothalamus produce specific neurohormones, often referred to as releasing or inhibiting hormones. These include peptides such as thyrotropin-releasing hormone, corticotropin-releasing hormone, gonadotropin-releasing hormone, and growth-hormone-releasing hormone, as well as inhibitors like dopamine and somatostatin.345
• Transport: These neurohormones are stored in nerve terminals within the median eminence of the hypothalamus. Upon neural stimulation, they are released into a capillary network that feeds into the hypophyseal-portal veins.53
• Delivery: This portal system directs the blood—and the concentrated neurohormones it carries—directly to the anterior pituitary gland, bypassing the general circulation.13
• Regulation: Once they reach the anterior pituitary, these substances bind to target cells to either stimulate or inhibit the secretion of pituitary hormones into the bloodstream.54

This mechanism allows the brain to integrate neural and environmental signals, such as stress, into the regulation of the endocrine system.23