At any stage of development, follicle degeneration (atresia) can occur. The granulosa cells die, and the oocyte degenerates as a result. The basement membrane that separates the oocyte from the granulosa cells frequently thickens to form the glassy membrane. The granulosa cells are replaced by fibrous material.

If fertilization does not occur, the corpus luteum involutes to form the fibrous tissue-filled corpus albicans. The corpus luteum's secretory cells degenerate and are phagocytosed by macrophages.

The granulosa lutein cells have a steroid-producing cell appearance, with pale cytoplasm indicating the presence of lipid droplets. Theca lutein cells are smaller and darker in color. If fertilization and implantation occur, hCG will keep the corpus luteum active as the corpus luteum of pregnancy.

The corpus luteum is the endocrine remnants of the follicle that has collapsed. The blood clot that formed after ovulation is still present in the center. Glanulosa lutein cells surround the clot, and theca lutein cells surround it on the outside.

The Graafian follicle is the follicular stage that occurs after the first meiotic division but prior to ovulation. As a result, it contains a 2N haploid oocyte. It is distinguished by a large follicular antrum that occupies the majority of the follicle. The secondary oocyte is located eccentrically after the first meiotic division. It is…[Read more]

The presence of a follicular antrum within the granulosa layer distinguishes secondary follicles from primary follicles. This space is filled with a fluid called liquor folliculi. The oocyte and the zona pellucida are also visible in this image. The theca interna, which produces hormones, surrounds the follicle.

When follicular cells proliferate into a stratified epithelium known as the zona granulosa, the follicle reaches the late primary follicle stage. This image shows the zona pellucida even more clearly.

The primary follicle has a central oocyte and is surrounded by a single layer of cuboidal cells. The zona pellucida is a thin band that separates these two layers.

Before releasing its ovum, an ovarian follicle goes through several stages. A limited number of primordial follicles form in the fetal ovary during the first five months of development. Oocytes are surrounded by a single layer of squamous follicular cells in these follicles. These primordial follicles are still undergoing the first meiotic…[Read more]

[Read more]

[Read more]

The Fallopian tube's inner mucosal layer is responsible for delivering gametes and embryos, as well as tubal fluid discharges. Epithelial cells and the lamina propria mucosa, a network of connective tissue with a mixed cell population, make up the endosalpinx. Ciliated epithelial cells and nonciliated secretory epithelial cells make up the…[Read more]