Question

What are the four phases of the menstrual cycle?

Answer 1

Menstrual cycle.

1. It is also called the reproductive cycle.
2. start at puberty called menarche
3. It is repeated at an average interval of 28/29 days.
4. Four phases are the menstrual phase, the follicular phase, ovulation, and the luteal phase.

1. Menstruation

1. In this phase blood flow from the vagina
2. It lasts for 3-5 days
3. It occurs due to the breakdown of the endometrial lining of the uterus
4. It occurs only when the ovum is not fertilized.

2. The Follicular phase

1. It is also called the proliferative phase.
2. After the menstrual phase, the follicular phase occurs.
3. In this phase endometrium of the uterus prepares for the next cycle.
4. The maturation of follicles takes place.
5. Primary follicle changes into the Graafian follicle.
6. Gonadotrophin hormone ( LH and FSH ) levels increase during this phase.
7. The growing follicle also starts to secrete estrogen.
8. It continues for 10- 13 days

3. Ovulatory phase

1. It occurs in the middle of the cycle that is 14th day
2. At this phase LH and FSH are high.
3. Rapid secretion of LH takes place and reaches maximum level during the mid-cycle called LH surge.
4. During LH surge Graafian follicle ruptures and releases ovum called ovulation

4. Luteal phase

1. The ovulatory phase is followed by the luteal phase.
2. During this phase rupture of the Graafian follicle changes to the corpus luteum.
3. Progesterone level is high during this phase it is secreted by the corpus luteum.
4. It is necessary for endometrium development.
5. So implantation takes place if the ovum is fertilized and leads to pregnancy.
6. It lasts for 15-28 days.