Hormonesecreting

Hormonesecreting, often written as hormone-secreting, refers to cells, tissues, or glands that synthesize and release hormones. In biology, hormone-secreting cells are a core component of the endocrine system, producing chemical messengers that regulate metabolism, growth, development, reproduction, and homeostasis.

Hormone secretion is typically regulated. Secretory cells may release hormones constitutively or in response to signals from the nervous system, other hormones, or changes in the internal environment. Most endocrine hormones are released into interstitial fluid and then into the bloodstream, allowing actions at distant target organs. Some cells in neuroendocrine tissues release hormones directly into the bloodstream in response to neural input. Receptors on target cells determine the specificity and magnitude of hormonal responses.

Prominent hormone-secreting tissues include the pituitary gland, thyroid, parathyroids, adrenal glands, pancreas, gonads, and pineal gland. Additional tissues such as the gastrointestinal tract, adipose tissue, kidneys, and heart also secrete hormones that influence digestion, appetite, ion balance, and blood pressure. Examples include insulin and glucagon from the pancreas; thyroid hormones T3 and T4; cortisol and adrenaline from the adrenal glands; leptin from adipose tissue; and erythropoietin from the kidneys.

Clinical relevance: disorders of hormone secretion underlie many diseases, including diabetes mellitus, hypo- and hyperthyroidism, Cushing's syndrome, Addison's disease, and pituitary disorders. The term is also used in pathology to describe tumors or lesions that autonomously secrete hormones, producing clinically recognizable syndromes.