At the end of the cycle many leucocytes can be found in the endometrium. A few hours before menstruation there is stasis of blood followed by vasoconstriction. During this period of desquamation major portions of the stratum compactum and spongiosum are shed. Regression rather than cell death is the characteristic of menstruation with the bulk of the basal zone remaining to reconstitute the functional zone of the endometrium during the next cycle. The cervix and uterine tube take no part in menstrual bleeding.
Stroma is compact with cells stellate with sparse cytoplasm.
First 7 are associated with glandular changes and last 7 with stromal changes. Glycogen vacuoles begin to appear in the basal portion of the gland early in the secretory phase. The appearance of these subnuclear glycogen vacuoles causes a loss of nuclear pseudostratification. Glycogen is secreted into the lumen of the glands. Secretion into the glands begins to decline.