Which of the following hormones is responsible for Milk Ejection?

Appeared in: MP CHO-2020

Explanation

Oxytocin is the hormone responsible for the milk ejection or 'let-down' reflex.
It is released from the posterior pituitary gland in response to stimuli like the baby suckling or crying.
Oxytocin acts on the myoepithelial cells that surround the alveoli in the mammary glands.
The contraction of these cells squeezes the milk from the alveoli into the ducts, making it available for the infant.

Option A: Oestrogen's primary role during pregnancy is the development of the breast's ductal system. High levels of oestrogen actually inhibit milk secretion before delivery.
Option B: Progesterone is responsible for the growth and development of the milk-secreting lobules and alveoli. Like oestrogen, it inhibits the actual secretion of milk during pregnancy.
Option D: Prolactin is responsible for milk production or synthesis within the alveolar cells of the breast, not its 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.
A key nursing role is to educate and support breastfeeding mothers. Understanding the let-down reflex is vital for troubleshooting common breastfeeding issues.
Nurses can advise mothers that factors like stress, pain, anxiety, and embarrassment can inhibit the release of oxytocin and interfere with the let-down reflex. Creating a calm, private, and comfortable environment is crucial for successful breastfeeding.
Promoting skin-to-skin contact, encouraging the mother to look at or think about her baby, and ensuring she is well-hydrated and comfortable can all help stimulate the oxytocin reflex.

How to Approach the Question

First, identify the key action in the question: 'Milk Ejection'.
Differentiate this term from 'milk production'. 'Ejection' implies an active process of pushing out, while 'production' is about synthesis.
Recall the two main hormones of lactation: Prolactin and Oxytocin.
Associate Prolactin with 'P' for Production.
Associate Oxytocin with the active 'squeezing' or 'ejection' action.
Eliminate Oestrogen and Progesterone, as their primary roles are in breast development during pregnancy and they inhibit lactation before birth.

Concept Tested & Keywords

QSPDTOHrbf7VTrxieUYDFt

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

E6 Nutrition Kumud Khanna 2e p. 99-101

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

Practise the full MP CHO-2020

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