Question

Which hormone will be responsible to release first milk from this gland?

• A. Prolactin
• B. Oxytocin
• C. Progesterone
• D. Luteinizing Hormone

Answer 1

The correct option is B Oxytocin

Oxytocin is a posterior pituitary hormone. It is responsible for uterus contraction leading to childbirth and ejection of milk from breasts. The signals for parturition originate from the fully developed fetus and the placenta, which induce mild uterine contractions, called as fetal ejection reflex. This triggers the release of oxytocin from the maternal pituitary. Oxytocin acts on the uterine muscle and causes stronger uterine contractions, which in turn stimulates further secretion of oxytocin. The stimulatory reflex between the uterine contraction and oxytocin secretion continues resulting in stronger and stronger contractions. This leads to the expulsion of the baby out of the uterus through the birth canal parturition. Soon after the infant is delivered, the placenta is also expelled out of the uterus. The mammary glands of the female undergo differentiation during pregnancy and start producing milk towards the end of pregnancy by the process, called as lactation.