Why the chances of pregnancy are very low in a lactating women till six months after delievery?
a.)High levels of HCG in women kill sperms
b.)High levels of estrogen and progesterone, secreted by the corpus luteum, that inhibit the secretion of gonadotropins.
c.)High levels of prolactin, inhibit the secretion of gonadotropins
d.)All of these

A: Lactational amenorrhoea is one of the natural method of birth control. R: High level of protactin inhibits the secretion of gonadotropins.

Assertion : Estrogen level is high during the follicular phase of menstrual cycle . Reason : During this phase corpus luteum secrete large amount of estrogen .

Go through the following statement (i) Relaxin produced by the ovary, facilitates delivery of the foetus by softening the connective tissue of pubic symphysis and relaxing the pelvic ligaments and joints. (ii) By the end of fifth month of pregnancy, the foetus develops limbs and digits. (iii) Thalidomide is a teratogenic drug which causes a condition called phocomelia. (iv). Although the levels of prolactin are high during pregnancy, milk secretion does not occur because of the high oestrogen and progesterone levels which make the breast unresponsive to the prolactin. Which of these are correct?

Choose the incorrect statement with reference to menstrual cycle (A) Gonadotropins attain a peak level in the middle of the cycle (B) Progesterone is secreted only during luteal phase (C) "LH" surge induces rupture of the Graafian follicle resulting in ovulation (D) Estrogen is secreted only during follicular phase

You have learnt that a characteristic feature on endocrine system is the presence of feedback loops. By this what is meant if hormone A stimulates gland 'X' and secrete hormone B, the production of ‘A' could be modified when the level of B changes in our blood. An example is the relation between hormones LH and estrogen (E_(2)) . An old woman exhibits the following features : High levels of LH in blood but low levels of E_(2) , in the blood. Another woman exhibits high level of LH in blood and also high level of E_(2) , in the blood. Where is the defect in both these women? Provide suitable diagram to support this answer.

Arrange the events in human female menstrual cycle a-Secretion of FSH, b-Growth of corpus luteum, c-Growth of follicle and oogenesis, d-Ovulation, e-Sudden increase in level of LH

Some important events in the human female reproductive cycle are given below. Arrange the events in a proper squence. A- Secretion of FSH, B - Growth of corpus luteum, C- Growth of the follicle and oogenesis, D- Ovulation E - Sudden increase in the levels of LH.

Go through the following statement:- (i) In both pre-pubertal and post-meno-pausal females, there are low levels of female sex hormones and high levels of gonadotrophins. (ii) There is no bleeding in an oestrous cycle as the broken endometrium is absorbed. (iii) Oestrogen is mainly secreted by the granulosa cells and progesterone mainly by the theca cells (iv) Some of the menopausal symptoms can be reversed HRT wherein a small sode of gonadotrophins is given to the patient. Which of these are correct?