Membrana granulosa

Membrana granulosa is a layer of cells that surround the ovum in the ovarian follicle. It plays a crucial role in the development and maturation of the ovum, as well as in the production of sex hormones.

Structure

The membrana granulosa is composed of granulosa cells, which are derived from the stroma of the ovary. These cells proliferate and differentiate during the follicular phase of the menstrual cycle, forming a multilayered structure around the ovum. The granulosa cells are connected by gap junctions, which allow for communication and coordination of their functions.

Function

The primary function of the membrana granulosa is to support the development and maturation of the ovum. The granulosa cells produce oocyte maturation inhibitor, which prevents the premature maturation of the ovum. They also produce FSH receptors, which respond to follicle-stimulating hormone (FSH) from the pituitary gland.

In response to FSH, the granulosa cells synthesize and secrete estrogen. This hormone promotes the growth and development of the endometrium, preparing it for potential implantation of a fertilized ovum.

The membrana granulosa also plays a role in the production of progesterone, which is essential for maintaining pregnancy. After ovulation, the granulosa cells transform into lutein cells, which produce large amounts of progesterone.

Clinical significance

Abnormalities in the membrana granulosa can lead to various reproductive disorders. For example, mutations in the FSH receptor can result in ovarian hyperstimulation syndrome, a condition characterized by excessive growth of the ovarian follicles. Additionally, granulosa cell tumors, which are a type of ovarian cancer, originate from the granulosa cells of the membrana granulosa.

See also

• Ovarian follicle
• Ovulation
• Menstrual cycle
• Sex hormone