Question

35. Menstrual cycle, choose the wrong statement. * (1 Point) Averages 28 days. O Secretory phase is under the influence of FSH. Variations between 21 and 35 days are normal. 0 Proliferative phase is under the influence of estrogen. In the Luteal /secretory phase, spiral arterioles develop in length and coil.

Answer 1

Menstrual cycle is the cyclical changes observed in uterus in response to hormones in women. It starts with the menstruation, then proliferative and ends with luteal phase. Ovulation separates the proliferative and luteal phase. Menstrual phase involved breakdown of the endometrial tissue due to loss of ovarian hormones. Proliferative phase is initiated by rising estrogen levels. Endometrial cells will undergo proliferation in response to estrogen which is mitogenic. Luteal phase is under the influence of progesterone, where endometrial cells undergo differentiation to prepare themselves for incoming embryo for implantation. Changes in the spiral arteries occur in response to progesterone in secretory phase. They will lengthen and then get coiled, in order to increase blood flow to endometrium in anticipation of the embryo.

The menstrual cycle varies between 21-35 days with an average length of 28 days. For a menstrual cycle of 28 day, day 14 is day of ovulation. Menses is around 1-5 days.

The ovarian cycle is made up of follicular, luteal and ovulation phase. The luteal phase is where the dominant follicle is recruited. FSH levels are low in luteal phase which corresponds to secretory phase of menstrual cycle. It is the follicular phase that FSH induced secretion of estrogen by granulosa cells of the follicle. Follicular phase corresponds to the proliferative phase in the menstrual cycle.

Right choice: Secretory phase is under the influence of FSH.