In the uterine glands uterus are shaped tube lined by ciliated columnar epithelium.
They are small in the unimpregnated uterus, but shortly after impregnation become enlarged and elongated, presenting a kinked or wavy appearance.
Uterine glands function
Uterine glands synthesize and secrete or transport substances essential for survival and development of the embryo or fetus and associated extra embryonic membranes.
Some components secretary of the uterine glands are absorbed by the secondary yolk sac lining the cavity exocoelomic during pregnancy, and it can help in providing fetal nutrition.