Graanulidosaatorid

Graanulidosaatorid, also known as granulosa cells, are a type of somatic cell found in the ovaries of females. They play a crucial role in the development and maturation of ovarian follicles. Granulosa cells are named for their granular appearance under a microscope, which is due to the presence of lipid droplets and glycogen within their cytoplasm. These cells are derived from the germinal epithelium and are essential for the production of estrogen, a hormone that is vital for the growth and maintenance of the female reproductive system.

During the early stages of follicle development, granulosa cells surround the oocyte (immature egg cell) and form the primary follicle. As the follicle grows, granulosa cells proliferate and differentiate into two main types: theca interna cells and granulosa cells proper. The granulosa cells proper are further divided into two subpopulations: the granulosa cells of the outer layer and the granulosa cells of the inner layer. The outer granulosa cells are more proliferative and produce anti-Müllerian hormone (AMH), while the inner granulosa cells are more secretory and produce estrogen.

Estrogen production by granulosa cells is regulated by follicle-stimulating hormone (FSH) from the pituitary gland. As the follicle matures, the granulosa cells become more secretory, and their estrogen production increases. This estrogen, in turn, stimulates the theca interna cells to produce androgens, which are then converted into estrogen by the granulosa cells. This feedback loop ensures the proper development and maturation of the follicle.

In the final stages of follicle development, the granulosa cells undergo a process called luteinization, where they transform into luteal cells. These luteal cells are responsible for the production of progesterone, another crucial hormone for the maintenance of the corpus luteum and the preparation of the endometrium for potential implantation of a fertilized egg. The corpus luteum, formed by the luteinized granulosa cells, plays a vital role in the menstrual cycle and pregnancy.