pituitari

Pituitari, or pituitary gland, is a small endocrine gland located at the base of the brain in a bony cavity called the sella turcica. It is connected to the hypothalamus by the infundibulum and functions as a major control center of the endocrine system. The pituitary consists of two anatomically and functionally distinct parts: the anterior pituitary (adenohypophysis) and the posterior pituitary (neurohypophysis).

The anterior lobe produces several releasing hormones under hypothalamic control and secretes thyroid-stimulating hormone (TSH), adrenocorticotropic hormone (ACTH), growth hormone (GH), prolactin (PRL), and the gonadotropins luteinizing hormone (LH) and follicle-stimulating hormone (FSH). The hypothalamus regulates these hormones via a specialized portal blood system, the hypophyseal portal system, delivering releasing and inhibiting hormones from the hypothalamus to the anterior pituitary.

The posterior lobe stores and releases vasopressin (antidiuretic hormone, ADH) and oxytocin, which are synthesized in hypothalamic neurons and transported down their axons. The different embryological origins reflect their dual nature: the anterior lobe arises from oral ectoderm (Rathke’s pouch), while the posterior lobe develops from neural tissue of the diencephalon.

Functions of pituitary hormones influence growth, metabolism, stress response, reproduction, lactation, and water balance. Disorders can include pituitary adenomas producing excess hormones (e.g., GH leading to acromegaly; ACTH leading to Cushing disease; prolactin causing hyperprolactinemia) or hormone deficiency (hypopituitarism). Diagnosis often involves hormone assays and imaging, with MRI as standard for lesion detection. Treatments vary from hormone replacement to surgical or radiotherapeutic approaches.