Uterus in late proliferative phase (100X)

Here it is possible to see that the endometrium can be divided into two parts. The part closest to the myometrium is called the basal layer or stratum basale, and this part is rich in cells – and the layer has an undifferentiated appearance.  The outer and much thicker layer is the functional layer or the stratum functionale. The glands are more developed and the stroma is less densely packed with cells. Stratum basale is not lost during the menstruation, and gives rise to a new functional layer during each menstrual cycle.