Question

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(a) Explain menstrual cycle in human females.

(b) How can the scientific understanding of the menstrual cycle of human females help as a contraceptive measure ?

Answer 1

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(a) Menstrual cycle in Human females-
(i) Menstrual Phase : Menstrual flow occurs between day 1-day 5 due to breakdown of the endometrial lining of the uterus, when fertilisation does not occur.

(ii) Follicular Phase : Primary follicles grow to mature Graafian follicles and the endometrium regenerates through proliferation because of changes induced by the pituitary and ovarian hormones.

(iii)Ovulatory Phase : Because of LH surge around th 14th day, the Graafian follicle gets reptured to release the secondary oocyte.

(iv) Luteal Phase: The ruptured Graafian follicle transforms into Corpus Luteum which secretes large amount of progesterone essential for maintaining endometrium.

(v) This phase is followed by implantation phase if the ovum gets fertilised. It enters into the next menstrual cycle if the ovum is not fertilised.

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(b) Scientific undersanding of the menstrual cycle of human females helps as a contraceptive measure, ovulation occurs during the mid cycle, the chances of fertilisation are very high. Hence the couples should abstain from coitus between day 10 - 17 of a cycle.