Question

What is the menstrual cycle? Which hormone regulates the menstrual cycle?

Answer 1

This is a monthly cycle that occurs in almost all females of the age 12 years and above. During this monthly cycle, females were using sanitary napkins.

Correct step by step answer:
The female reproductive cycle that is characterized by cyclic changes in the uterine lining is known as the menstrual cycle. The menstrual cycle is regulated by gonadotropin hormones secreted by the anterior pituitary (FSH and LH). This cycle is of 28 days when the menses take place on cycle days of 3- 5. The entire menstrual cycle consists of four phases such as menstrual phase, follicular phase, ovulatory phase and luteal phase.
Menstrual phase: During this phase, the production of luteinizing hormone from the anterior lobe of the pituitary gland is reduced. This results in the degeneration of the Corpus luteum and also reduces the production of progesterone and oestrogen. Then the androecium of the uterus breaks and menstruation begins, the menstrual flow is constituted by the endometrium secretion, blood and unfertilized ovum.
<>Follicular phase:_ the follicular phase Includes cycle days of 6 to 13 or 14 in a 28 days cycle. During this phase, the follicle- stimulating hormone(FSH) is secreted by the anterior lobe of the pituitary gland to stimulate the secretion of oestrogen from the ovarian follicle. Then proliferation of the endometrium of the uterine wall is done by oestrogen. This will cause thickening of the endometrium followed by uterine glands & blood vessels.
Ovulatory phase: This phase is the middle of the cycle i.e., about the 14th day when LH and FSH attain a peak level results in rupturing of the graafian follicle, the release of the ovum, the concentration of oestrogen in blood increases and causes ovulation to occur.
- Luteal Phase: this phase includes cycle days 15 to 28. During this phase, progesterone is secreted by corpus luteum. Thickening of the endometrium occurs, and uterine glands become secretory.

Note:
- The follicle-stimulating hormone (FSH) stimulates the ovarian follicles to produce oestrogens.
- Luteinizing hormone (LH) stimulates corpus luteum to secrete progesterone.
- The menstrual phase is caused by the increased production of oestrogens.
- LH also causes ovulation to occur.
- During the menstrual cycle the proliferative phase is caused by the increased production of oestrogens and the secretory phase is caused by increased production of progesterone.