1. what we mean by lining of the uterus?(menstrual phase.)
2. shedding of uterine lining.explain?

1. The endometrium is the innermost mucous lining of the uterus. During menstrual cycle, the endometrium becomes thick and is richly supplied with blood vessels to receive the fertilised egg.
2. During the menstrual cycle, if fertilisation does not occur, the endometrial lining of the uterus and its blood vessels shed or break down and mix with blood, mucus and other cell debris to form menses. The menses are discharged through the vagina as menstruation or menstrual flow which lasts for three to five days from the beginning of the menstrual cycle.