Final answer:
The phase of the menstrual cycle during which the endometrium is shed, accompanied by bleeding and the loss of mucus and cellular debris, is menstruation, typically covering days 1 to 5 of the cycle.
Step-by-step explanation:
Menstrual Cycle Phases
The phase of the menstrual cycle during which the ischemic endometrium is shed along with a discharge of blood, mucus, and cellular debris is known as menstruation. During menstruation which generally occurs on days 1 to 5 of the cycle the endometrial tissue that built up in the previous cycle degenerates and the layer of cells called the stratum functionalis is shed from the uterus.