Question

Why does menstruation occur?

Answer 1

Hint: Menstruation is a biological process which is related to the female reproductive system of the humans, and this menstruation can also be seen in some primates, and it mainly occurs due to a fall and rise in the levels of estrogen and progesterone hormones which are sex hormones produced by the ovaries.

Complete answer:
- The female reproductive system consists of a pair of ovaries, and they contain eggs or ovum which are not matured and they generally formed during the embryonic stage itself.
- The number of this ovum is reduced when a child grows and attains the age of puberty.
- Girls obtain menstruation during puberty and it occurs at the age of 11 to 15. Nowadays it may appear at the age of 8, which may also be normal.
- The first obtaining menstruation is called menarche, during puberty, some follicles which contain eggs have matured and compete to release, but among those only one ripened ovule is released and this process is called ovulation, and this ovulation Is under the control of luteinizing hormone.
- Once ovulation occurs, an egg that is released waits for the sperm to fertilize, in the meanwhile, the corpus luteum releases a large amount of progesterone which helps in preparing the uterus for implantation.
- Uterus undergoes a lot of changes where there is an increase in the blood supply to the endometrial walls and they have stored glycogen and cells are increased in size.
- If fertilization does not occur within the 24 hrs, the follicle of the ovum undergoes disintegration and degeneration, and there is a fall in the levels of hormones such as estrogen and progesterone.
- This causes the shrinking and shredding of the uterine endometrial wall, and they appear as bleeding which lasts for 3 to 7 days.
- This menstruation ceases at the age of 45 to 55 years which is called menopause.
- And this process had 2 cycles which are ovarian cycle for ovulation and the other is a menstrual cycle for menstruation.

Note: To explain it simply, menstruation occurs if the released egg is not fertilized by a certain period, and if not happens, the hormones which are raised are fall abruptly that cause the shedding of the uterine wall which is called as period, and the menstrual cycle in healthy individuals are range from 21 to 35 days and average it is 28 days.