Answer
Endometrium is a highly vascular secretory epithelium that supplies oxygen and nutrients needed to sustain a fertilized egg; the myometrium is a thick layer of smooth muscle fibers that supports the uterine wall during pregnancy, and contracts to expel the fetus.
Work Step by Step
The wall of the uterus has three layers of tissues -- the perimetrium, the myometrium ( middle layer) and the endometrium ( nearest the lumen).
The perimetrium consists of simple squamous epithelium on areolar connective tissue basement membrane. The myometrium comprises three layers of smooth muscles; the middle fibers are circular, and the inner and outer fibers are longitudinal or oblique. During labor, the contraction of the myometrium under the the stimulation of pituitary(PP) oxytocin is an important factor in the expulsion of the fetus from the birth canal. The endometrium which borders the uterine lumen is basically simple columnar epithelium over areolar connective tissue . The innermost layer of the endometrium develops many mucus-secreting glands .
Functionally, the endometrium is consdered to have two parts --the functional layer, and the basal layer. It is the highly vascularized functional layer of the endometrium that is lost during menstruation. The stem cells of the stratum basalis ( basal layer) reconstitute the stratum functionalis ( functional layer) after menstruation
