Which hormone is primarily responsible for controlling the milk-let-down (milk ejection) reflex during lactation?

• A. Estrogen
• B. Oxytocin
• C. Follicle-stimulating hormone (FSH)
• D. Prolactin

Answer: (B)

Verified step by step guidance

1. Understand the milk-let-down reflex: This reflex is the process by which milk is ejected from the mammary glands during lactation, allowing the infant to feed.
2. Identify the hormones involved in lactation: Prolactin is responsible for milk production, while oxytocin controls the milk ejection or let-down reflex.
3. Recall the role of oxytocin: Oxytocin is released from the posterior pituitary gland in response to suckling, causing the myoepithelial cells around the alveoli in the mammary glands to contract and eject milk.
4. Differentiate from other hormones: Estrogen primarily regulates the development of mammary tissue, and FSH is involved in reproductive processes but not milk ejection.
5. Conclude that oxytocin is the hormone primarily responsible for the milk-let-down reflex during lactation.