The hormone responsible for the ejection of breast milk is?

IGNOU Post B. SC. Nursing entrance-2019

Obstetrics & Gynaecology

Easy

Appeared in: IGNOU Post B. SC. Nursing entrance-2019

Explanation

Oxytocin is the hormone responsible for the ejection of milk from the mammary glands, a process known as the milk let-down reflex.
It is released from the posterior pituitary gland in response to the infant suckling the nipple.
Oxytocin stimulates the contraction of myoepithelial cells that line the alveoli and ducts of the breast.
This contraction forces the milk that has been produced into the ductal system and out through the nipple, making it available to the infant.

Option A: Estrogen, along with progesterone, promotes the growth and development of the breast's ductal system during pregnancy but actually inhibits the secretion of milk.
Option B: Progesterone is essential for the development of the breast's lobule-alveolar system during pregnancy, but it inhibits the actual secretion of milk. Its levels must fall after birth for lactation to begin.
Option D: Prolactin is the hormone responsible for milk production (lactogenesis), not ejection. It stimulates the alveolar cells to synthesize milk.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Hormonal control of lactation, specifically the milk ejection reflex as background academic context rather than a clinical decision trigger.
A key nursing role is to educate new mothers on factors that can facilitate or inhibit the let-down reflex. Stress, pain, and anxiety can inhibit oxytocin release, making breastfeeding difficult.
Nursing interventions to promote milk ejection include ensuring the mother is in a comfortable, relaxed environment, encouraging skin-to-skin contact, managing postpartum pain effectively, and teaching gentle breast massage.
What if? A mother reports that her breasts feel full but the baby is frustrated and not getting much milk. This suggests a problem with milk ejection, not production. The nurse should assess for inhibitors like pain or stress and implement relaxation techniques, rather than immediately suggesting formula supplementation.

How to Approach the Question

First, identify the key term in the question: 'ejection' of breast milk.
Recognize that lactation involves two distinct hormonal actions: production and ejection.
Recall the specific functions of the hormones listed in the options related to lactation.
Differentiate between Prolactin, which is for 'Production', and Oxytocin, which is for 'eJection' (let-down). A simple mnemonic is 'P for Production, O for Out'.
Eliminate Estrogen and Progesterone, as their primary role during pregnancy is to develop the breast tissue while inhibiting milk secretion.
Select the hormone that directly causes the muscular contraction needed to expel milk from the alveoli.

Concept Tested & Keywords

Concept Tested: Hormonal control of lactation, specifically the milk ejection reflex.
Stem keywords: hormone, ejection, breast milk
Lead-in keywords: responsible for
Negative lead-in flag: false

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