Ovary: corpus luteum

The corpus luteum is present and actively secreting progesterone and estrogen from days 15-26 of the menstrual cycle. A portion of a corpus luteum extends across the bottom of this image of the ovary. This portion of the corpus luteum represents approximately 25-30% of its total volume. 10x

Granulosa lutein cells differentiate from the stratum granulosum of the follicle and comprise the main mass of the corpus luteum. Each cell resembles a typical steroid-producing cell with frothy cytoplasm and an euchromatic nucleus.

Theca lutein cells arise from the theca interna of the follicle. These cells stain more intensely and are smaller than the granulosa lutein cells. Theca lutein cells are located more peripherally around the corpus luteum and form the infoldings into the structure.

A number of atretic (secondary) follicles occupy a large portion of the image.

The next image is similar to that outlined by the rectangle.