The hormone primarily responsible for the milk ejection?

Appeared in: Tripura CHO - 2021

Explanation

The hormone primarily responsible for milk ejection (the let-down reflex) is Oxytocin.
Oxytocin is released from the posterior pituitary gland in response to suckling.
It acts on the myoepithelial cells surrounding the breast alveoli, causing them to contract.
This contraction forces the milk from the alveoli into the ducts, making it available to the infant.

Option A: Oestrogen is primarily involved in the growth and development of the breast's ductal system during pregnancy.
Option B: Progesterone is essential for the development of the breast's lobules and alveoli during pregnancy.
Option C: Prolactin is the hormone responsible for milk production (synthesis), not ejection.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Hormonal control of lactation as background academic context rather than a clinical decision trigger.
Understanding the milk ejection reflex is crucial for nurses counseling new mothers on breastfeeding.
The reflex can be inhibited by stress, pain, or anxiety. Nurses should advise mothers to find a comfortable, relaxing environment for breastfeeding to facilitate the let-down reflex.
Pain from cracked nipples or post-delivery discomfort can interfere with oxytocin release. Proper latching techniques and pain management are key nursing interventions.

How to Approach the Question

This is a factual recall question testing knowledge of endocrine physiology.
First, identify the specific process asked in the question: 'milk ejection'.
Differentiate this key process from 'milk production' or 'breast development', as different hormones are responsible for each.
Recall the primary hormones involved in lactation: Prolactin, Oxytocin, Oestrogen, and Progesterone.
Associate Prolactin with milk production (synthesis).
Associate Oxytocin with milk ejection (let-down).

Concept Tested & Keywords

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E6 Physiology Guyton 4SAE Part 3 p. 69-71

E6 Physiology Essentials Sembulingam 10e Part 2 p. 30-32

E6 Obstetrics Williams p. 48-68

Practise the full Tripura CHO - 2021

Attempt every question from this paper in a timed mock, then review the full solution for each one.