Which statement correctly describes the vascular route by which hypothalamic releasing hormones reach the anterior pituitary?

• A Internal carotid artery branches deliver them directly to anterior pituitary sinusoids
• B Capillaries of the median eminence drain into long portal veins that perfuse the anterior pituitary sinusoids ✓
• C They travel down axons of tuberoinfundibular neurons to be stored in posterior pituitary terminals
• D Short portal veins carry them retrogradely from the anterior to the posterior pituitary

Explanation

Releasing hormones are secreted by hypothalamic neurons into the capillary plexus of the median eminence, supplied by the superior hypophyseal artery. These capillaries coalesce into long hypophyseal portal veins that descend along the stalk and break up into sinusoids of the anterior pituitary, delivering releasing factors at far higher concentrations than systemic blood achieves. Axonal transport to posterior pituitary terminals applies only to ADH and oxytocin.

Reference: Gray's Anatomy for Students, 4th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.