Question

Regarding assertion and reason, choose the correct statement:

Assertion (A): The uterus of a nursing mother returns to its normal size after pregnancy.
Reason (R): Oxytocin is responsible for uterine contractions.

• A. A is true R is false
• B. Both A and R are true and R explains A
• C. A is false and R is true
• D. Both A and R are true but R does not explain A

Answer 1

The correct option is B Both A and R are true and R explains A

Oxytocin stimulates the milk-ejection reflex and causes milk to be ejected from the ducts through the nipple. During suckling, sensory receptors in the nipples send impulses to the hypothalamus, which triggers the release of oxytocin. Oxytocin is also needed to stimulate uterine contractions in women during childbirth. Oxytocin secretion continues after childbirth in a woman who is breastfeeding, which is why the uterus of a nursing mother returns to its normal size after pregnancy more quickly than does the uterus of a mother who does not breastfeed.