#hormones

• Adenohypophysis — The anterior and intermediate lobe of the hypophysis (pituitary gland), possessing an epithelial-glandular structure distinct from the neurohypophysis; it is responsible for the synthesis and secretion of most essential trophic hormones, such as growth hormone (GH), prolactin, ACTH, TSH, LH, and FSH. This structural component regulates the metabolic activity and homeostasis of the entire endocrine system through complex feedback mechanisms.
• Agonadism — A highly rare congenital medical condition characterized by the complete structural and functional absence of gonads (testes or ovaries), caused by an anomaly in early embryonic development; it results in a lack of sex hormones and requires life-long hormone replacement therapy.
• Androgen — A natural or synthetic hormonal substance (such as testosterone) that stimulates and controls the development and maintenance of male secondary sexual characteristics in vertebrates. As an adjective, it describes any factor, chemical compound, or structural physiological process that induces masculinization or exerts a direct influence on the male reproductive organs.
• Angiotensin — A peptide hormone with potent vasoconstrictive action, derived from a plasma precursor (angiotensinogen) through an enzymatic cascade involving renin and angiotensin-converting enzyme (ACE). This well-defined structural element plays a fundamental role in regulating arterial blood pressure, stimulating aldosterone secretion by the adrenal glands, and maintaining fluid and electrolyte balance in the body, while also serving as the primary target for modern antihypertensive treatments.
• Adenohypophysis — The anterior lobe of the pituitary gland, of ectodermal origin, with a highly specialized epithelial glandular structure; adenohypophysis. This major component of the endocrine system synthesizes and secretes fundamental tropic hormones into the bloodstream that control somatic growth, thyroid function, adrenal gland activity, and reproductive system dynamics, being directly regulated by hypothalamic neurohormones.
• Anterior pituitary — Pertaining to the anterior pituitary gland (the anterior lobe of the pituitary gland) or secreted by it; adenohypophyseal. The term describes cellular structures, vascular processes, or specific hormones (such as STH, ACTH, TSH, FSH, LH) responsible for regulating the activity of other endocrine glands and general metabolism.