Pituitary stalk
Infundibulum hypophysis
Endocrine & glandsGlandsHead
- What it is
- A thin funnel of nerve fibres and portal blood vessels that hangs the pituitary from the floor of the hypothalamus (the median eminence), passing through a hole in the diaphragma sellae.
- Function
- Carries hypothalamic axons to the posterior lobe and the hypophyseal portal veins that deliver releasing hormones to the anterior lobe.
- Size
- About 8–10 mm long, 2–3 mm in diameter
- Clinical note
- Anything that compresses the stalk (tumour, surgery, head injury) interrupts the dopamine brake on prolactin: prolactin rises while every other anterior hormone falls — the "stalk effect".