hormonets

Hormonets is the definite form of the Swedish noun hormon, used to refer to a chemical messenger produced by the endocrine system. In science, hormones regulate physiological processes by signaling distant target cells after being released into the bloodstream or other body fluids.

Most hormones are produced by endocrine glands, including the pituitary, thyroid, adrenals, pancreas, and gonads, or by neurosecretory cells in the hypothalamus. After secretion, hormones travel through the circulatory system to reach their target tissues and exert specific effects.

Action is achieved by binding to specific receptors on target cells. Peptide and amine hormones typically interact with cell-surface receptors and trigger signaling cascades, whereas steroid and thyroid hormones often cross the cell membrane and act through intracellular receptors that regulate gene transcription.

Major classes include peptide and protein hormones (for example insulin and growth hormone), steroid hormones derived from cholesterol (such as cortisol, estrogen, and testosterone), and amine hormones (like adrenaline and thyroid hormones).

Regulation occurs primarily through feedback mechanisms, notably the hypothalamic-pituitary axis, and is modulated by factors such as circadian rhythms, nutrition, and stress. Dysregulation can cause endocrine disorders, including diabetes mellitus, thyroid disease, and adrenal disorders.

Clinical use and research of hormones cover diagnosis, hormone replacement therapy, and the development of drugs that modulate endocrine signaling.