Menstruation is in progress, with breakdown of surface tissue. Slide 17 Overview of uterine wall in the early post-menstrual stage. Only the basal layer of endometrium is present. Glands are sparse. The endometrium has grown thicker under the influence of estrogen.
Glands are straight and thin.
Slide 19 View of a later proliferative stage. Glands are still quite straight and thin, but there is a noticeable difference between the darker, more compact basal and the paler, more edematous functional layer above. Slide 20 Endometrium in the early secretory stage. Glands are becoming tortuous and sacculated under the influence of progesterone. Their glycogen-rich mucoid secretion is stored within the glands, pending a possible implantation of an embryo.