Question

During which stage of the menstrual cycle does the uterine lining thicken and becomes engorged with blood?

a) Menstruation
b) Ovulation
c) Proliferative Phase
d) Secretory Phase

Answer 1

During the proliferative phase of the menstrual cycle, the uterine lining thickens and becomes engorged with blood, stimulated by rising estrogen levels.

Step-by-step explanation:

The stage of the menstrual cycle during which the uterine lining thickens and becomes engorged with blood is known as the proliferative phase. This phase is stimulated by the rising levels of estrogen which is secreted by the cells of the maturing ovarian follicle.

Estrogen promotes the growth of the uterine lining to prepare for potential implantation of a fertilized egg. Following the menstrual flow, the endometrium begins to proliferate again, signifying the start of the proliferative phase. This phase ranges from day 7 to 14 of the uterine cycle. After ovulation, the menstrual cycle enters the secretory phase, which is marked by the production of progesterone by the corpus luteum, leading to further changes that make the uterus receptive to the implantation of a blastocyst.