MEDICAL PHYSIOLOGY

Detailed explanation-1: -Estrogen causes the lining to grow and thicken to prepare the uterus for pregnancy. In the middle of the cycle, an egg is released from one of the ovaries (ovulation). Following ovulation, levels of another hormone called progesterone begin to increase.

Detailed explanation-2: -Progesterone and estrogen cause the lining of the uterus to thicken more, to prepare for possible fertilization.

Detailed explanation-3: -Two hormones produced from the ovaries thicken and prepare the uterine lining for implantation. Estrogen causes the thin uterine lining to thicken. Progesterone causes the thickened uterine lining to develop the characteristics needed for implantation.

Detailed explanation-4: -During the second phase of the menstrual cycle, the effects of progesterone result in the proliferation of the endothelial lining in the endometrium, resulting in a thickened endometrial wall. The result is an increased thickness and surface area of the endometrium in which implantation can occur.

Detailed explanation-5: -If the egg is fertilised, progesterone stimulates the growth of blood vessels that supply the lining of the womb (endometrium) and stimulates glands in the endometrium to secrete nutrients that nourish the early embryo.