During breastfeeding, the reflex responsible for milk ejection (let-down) differs from the reflex controlling milk production. The hormone directly responsible for milk ejection is secreted by the:

• A Anterior pituitary under dopaminergic stimulation
• B Ovary in response to rising FSH after placental separation
• C Posterior pituitary in response to nipple stimulation ✓
• D Adrenal cortex in response to the stress of labour

Explanation

Suckling sends afferent impulses from the nipple to the hypothalamus, causing release of oxytocin from the posterior pituitary. Oxytocin contracts the myoepithelial cells around the alveoli and ejects milk. Prolactin, released from the anterior pituitary, governs milk secretion rather than ejection, which is the distinction being tested. Dopamine actually inhibits prolactin, so option A fails on both counts.

Reference: Williams Obstetrics, 26th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.