Question

Menstrual flow occurs due to lack of:
(A) FSH
(B) Oxytocin
(C) Vasopressin
(D) Progesterone

Answer 1

Hint: The female reproductive system undergoes regular natural changes which ensures and helps the female gonads to produce viable gametes in the form of ovum or egg. The complete process of regular changes works in a coordinated manner. This cycle is known as the menstrual cycle and it is influenced by several types of hormonal influences.

Complete answer:
The menstrual cycle occurring in the females is a complex cycle as it works under the influence of several hormones. The main purpose of the menstrual cycle is the production of gametes in the form of ovum and also preparing and maintaining the uterus for possible pregnancy and implantation. If proper implantation does not occur, the fluctuation in the levels of different regulatory hormones cause the rupture of the environment of the uterus by disintegration of the blood capillaries and it leads to the menstrual flow. The hormones are produced by different glands which work in a coordinated way to influence and regulate the process of menstruation.
FSH or the follicle stimulating hormone induces gonad activity and is also called gonadotropins. In women, this hormone promotes the development of ovarian follicles in the ovary until the egg is released from one follicle at time of ovulation. It also increases the production of estradiol. Its deficiency can cause germ cell non-maturation.
Oxytocin secreted from the hypophysis. It is involved in causing intense contractions of the uterus during childbirth and the secretion of milk from the mammary glands.
Vasopressin is secreted from the hypophysis (posterior pituitary gland). It acts predominantly in the kidney and promotes the absorption of water and electrolytes through distal tubules, which decreases the loss of water by urine (diuresis). It is also considered an anti-diuretic hormone (ADH).
Progesterone is secreted by corpus luteum and is necessary for the maintenance of the endometrium. This endometrium is responsible for the implantation of the fertilized ovum. Thus, it protects the endometrium and support pregnancy, and its removal or lack results in menstrual flow or abortion.

Therefore, the option (D) is the correct choice.

Note: The menstrual cycle occurs in normal females as a regular cycle to generate an ovum for fertilization and implantation and it takes place due to the rise and fall of hormones. This cycle results in the thickening of the lining of the uterus by increasing the blood supply and the growth of an egg which is essential for pregnancy. In a natural cycle, menstruation or menstrual flow occurs when the levels of estrogen and progesterone decrease rapidly in case when there is no fertilization and subsequently, no implantation takes place.