Question

Menstruation flow occurs due to lack of
A. Progesterone
B. FSH
C. Oxytocin
D. Vasopressin

Answer 1

Hint: Menstruation flow is the event when fertilization of egg does not occur and there is no pregnancy.

Complete answer:
The reproductive cycle in the female primates is called menstrual cycle. The menstrual flow results due to breakdown of the endometrial lining of the uterus, which is maintained by the progesterone hormone, and its blood vessels which form liquid that comes out through vagina. Menstruation flow occurs due to lack of progesterone.

Additional information:
- Progesterone: Maintains the endometrial lining and pregnancy, its withdrawal results in menstrual flow or abortion respectively. It is released by the corpus luteum.
- FSH: Stimulates gonadal activity and hence is called gonadotropins. Its deficiency will cause non-maturation of germ cells. It is released by pituitary gland.
- Oxytocin: It stimulates vigorous contractions of the uterus at the time of childbirth and milk ejection from mammary glands. It is released by posterior pituitary gland.
- Vasopressin: Acts mainly in the kidney and stimulates reabsorption of water and electrolytes by the distal tubules and hence reduces the loss of water through urine. Thus, it is also called an anti-diuretic hormone (ADH). It is released by posterior pituitary gland.

Hence the correct answer is Progesterone.

Note: The major events of the menstrual cycle are menstruation, follicular phase, and the luteal phase.