Question

Which one of the following causes mammary glands to enlarge at puberty?

• A. Testosterone
• B. Progesterone
• C. Estrogen
• D. Oxytocin

Answer 1

The correct option is D Oxytocin

A. Testosterone is secreted by adrenal cortex of adrenal gland and testes. It stimulates the descent of testes and male pattern of development. It helps in development of secondary and accessory sexual characters in males.

B. Progesterone is secreted by corpus luteum of ovaries. It supports pregnancy. It acts on mammary glands and stimulates the formation of alveoli and milk secretion.

C. Estrogen is secreted by ovary. It stimulates the growth and activities of female secondary sex organs, development of growing ovarian follicles, appearance of female secondary sex characters, mammary gland development.

D. Oxytocin is secreted by pituitary gland. It acts on smooth muscles of the body and stimulates their contraction. It causes enlargement of mammary glands at puberty. Also, it stimulates a vigorous contraction of uterus at the time of birth and milk ejection from the mammary gland.

So, the correct answer is 'Oxytocin'.