MICROANATOMY

Detailed explanation-1: -If a fertilised egg implants in the lining of the uterus, the corpus luteum continues to produce progesterone, which maintains the thickened lining of the uterus. If pregnancy does not occur, the corpus luteum dies, progesterone levels drop, the uterus lining sheds and the period begins again.

Detailed explanation-2: -If fertilization does not occur, the endometrium, coupled with blood and mucus from the vagina and cervix (the lower, narrow part of the uterus located between the bladder and the rectum) make up the menstrual flow (also called menses) that leaves the body through the vagina.

Detailed explanation-3: -If the egg is not fertilized and an embryo does not implant, the corpus luteum deteriorates, and progesterone levels will fall. Without progesterone, the endometrium isn’t maintained and the uterus will start to shed its lining, resulting in menstruation.

Detailed explanation-4: -The progesterone prepares the body for pregnancy in the event that the released egg is fertilised. If the egg is not fertilised, the corpus luteum breaks down, the production of progesterone falls and a new menstrual cycle begins.