Explain the events in a normal woman during her menstrual cycle on the following days:

(a) Pituitary hormone levels from 8 to 12 days.

(b) Uterine events from 13 to 15 days.

(c) Ovarian events from 16 to 23 days.

(a) In a normal woman during her menstrual cycle, the Pituitary hormone levels from 8 to 12 days are low. The FSH and LH levels – low. During the menstrual period the pituitary gland produces hormones namely FSH (Follicle stimulating hormone) and LH (luteinising hormone)

8-12 days in menstrual cycle is follicular phase. The FSH and LH secretion increases gradually during this phase. In this phase follicular development takes place and estrogens is secreted by growing follicles.

(b) In a normal woman during her menstrual cycle, the Uterine events from 13 to 15 days are as follows:

- During these days the LH and FSH attain peak level

- The rapid secretion of LH leads to rupture of Graafian follicle and thereby ovulation (the release of ovum) takes place.

- This is ovulatory phase

- During these days Endometrium is highly vascularised

- And the Endometrium of uterus regenerates through proliferation.

- It is proliferative phase of uterine lining

(c) In a normal woman during her menstrual cycle, the ovarian events from 16 to 23 days are as follows:

- This is luteal phase

- During these days corpus luteum is formed. After ovulation the Graafian follicle transforms to corpus luteum.

- Progesterone is secreted with the help of corpus luteum.

- Progesterone helps in maintaining endometrium.