Question

(d) Which period is said to be period of regeneration of endometrium? 
 

Hint:

The proliferative phase (days 5-13) is when your body rebuilds the uterine lining after menstruation. Estrogen levels rise, stimulating the endometrium to thicken in preparation for a potential pregnancy. It's a time of renewal, so you might feel more energized as your body gears up for ovulation!

Answer 1

The proliferative phase (after menstruation, roughly days 5–13) when the endometrium is rebuilt.
The proliferative phase is the second phase of the menstrual cycle, occurring after menstruation, typically between days 5 and 13 of a 28-day cycle. During this phase, the endometrial lining (the inner layer of the uterus) is rebuilt and prepared for potential implantation of a fertilized egg. The main processes and hormonal changes during this phase include:
- Hormonal Changes: Estrogen levels rise as the developing follicles in the ovaries secrete this hormone. Estrogen stimulates the growth and regeneration of the endometrial lining, preparing it to support a fertilized egg.
- Endometrial Regeneration: After menstruation, when the endometrial lining has been shed, the lining starts to thicken and rebuild. The proliferation of the endometrial cells occurs, making the uterus more receptive to implantation. The glands and blood vessels in the endometrium begin to grow and become more complex.
- Follicular Development: During this phase, one dominant follicle in the ovary matures under the influence of FSH (follicle-stimulating hormone). This follicle produces increasing amounts of estrogen, which supports the growth of the endometrium.
- Cervical Mucus Changes: The cervical mucus becomes thinner, clearer, and more slippery, resembling raw egg whites. This facilitates sperm movement through the cervix into the uterus, creating an optimal environment for fertilization.
- Increased Blood Flow: The endometrial tissue receives increased blood flow, which prepares it to support an embryo in the event of pregnancy. This phase ends when ovulation occurs (around day 14), triggered by a surge in luteinizing hormone (LH) and FSH, signaling the release of the egg from the ovary.
The proliferative phase is essential for fertility, as the preparation of the endometrial lining is necessary for implantation. If ovulation occurs and the egg is fertilized, the endometrial lining will continue to support the embryo. If fertilization does not happen, the cycle continues into the secretory phase.