Parotid: in front of and below the ear. Submandibular: in the submandibular triangle. Sublingual: in the floor of the mouth. Minor glands: throughout the oral mucosa (lips, cheeks, palate, tongue).
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Neural only. Salivary nuclei in the medulla receive input from taste, oral touch, smell, higher centres and the hypothalamus. Aldosterone modifies duct Na⁺/K⁺ handling but does not control the volume secreted.
Epigastrium and left hypochondrium, behind the stomach and lesser sac, across L1–L2. The head lies in the duodenal C-loop and the tail at the splenic hilum.
Subperitoneal, in the lesser pelvis between the bladder neck (above) and the external urethral sphincter/perineal membrane (below), behind the pubic symphysis and in front of the rectum.
Deep perineal pouch, posterolateral to the membranous urethra, within the external urethral sphincter; ducts open into the bulbous part of the spongy urethra.
Anterior neck, deep to the infrahyoid (strap) muscles, at vertebral levels ≈C5–T1; lobes extend from the oblique line of the thyroid cartilage to about the 6th tracheal ring.
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TSH from the anterior pituitary (stimulates every step from iodide uptake to hormone release and causes hypertrophy/hyperplasia); iodide availability (excess acutely inhibits organification — Wolff–Chaikoff effect).
Posterior surface of the thyroid lobes: superior pair at the level of the cricoid cartilage; inferior pair near the inferior poles (variable, sometimes mediastinal).
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Ionised Ca²⁺ via CaSR (main); calcitriol inhibits PTH gene transcription; high phosphate and FGF-23 also modulate; severe hypomagnesaemia impairs PTH release (refractory hypocalcaemia).
Axillae, areolae and nipples, perianal region, mons pubis, labia majora and scrotum; modified forms in the external ear canal (ceruminous) and eyelids (Moll).
Viscous, protein- and lipid-rich secretion with steroids and ammonia precursors; odour results from bacterial metabolism.