hipotálamohipofisosuprarrenal

The hipotálamo-hipofisario axis, commonly referred to as the hypothalamic-pituitary axis, is a neuroendocrine system that integrates the nervous system with the endocrine system. It centers on the hypothalamus, a brain region that communicates with the pituitary gland, which sits at the base of the brain. The pituitary is divided into the anterior (adenohypophysis) and posterior (neurohypophysis) lobes, each with distinct control mechanisms and hormone outputs.

The hypothalamus regulates the anterior pituitary through a specialized network of releasing and inhibiting hormones delivered via the hypothalamic–hypophyseal portal system. Releasing hormones such as thyrotropin-releasing hormone (TRH), corticotropin-releasing hormone (CRH), gonadotropin-releasing hormone (GnRH), and growth hormone–releasing hormone (GHRH) stimulate pituitary secretion of thyroid-stimulating hormone (TSH), adrenocorticotropic hormone (ACTH), luteinizing hormone (LH), follicle-stimulating hormone (FSH), growth hormone (GH), and prolactin. Somatostatin and dopamine act as inhibitory signals for certain pituitary products. The posterior pituitary stores and releases hormones produced in the hypothalamus: vasopressin (antidiuretic hormone, ADH) and oxytocin.

Feedback mechanisms are essential to function. Hormones released from peripheral glands (such as cortisol from the adrenal cortex or thyroid hormones from the thyroid) typically feed back to suppress hypothalamic and pituitary activity, maintaining hormonal balance and responding to physiological needs.

Dysfunction of this axis can lead to a range of disorders, including growth abnormalities, reproductive issues, diabetes insipidus, and pituitary adenomas, each reflecting altered hormone production or regulation.