Granulosa cell: Difference between revisions

Revision as of 14:14, 21 February 2025

Granulosa cell

Granulosa cells are somatic cells of the sex cord that are closely associated with the developing female gamete, the oocyte, within the ovary. These cells play a crucial role in the development and function of the ovarian follicle, as well as in the production of sex steroids.

Structure

Granulosa cells are found in the ovarian follicles, which are the basic units of female reproductive biology. Each follicle contains an oocyte, surrounded by granulosa cells and theca cells. The granulosa cells form several layers around the oocyte and are involved in the formation of the zona pellucida, a glycoprotein layer surrounding the oocyte.

Function

Granulosa cells have several important functions:

Support of the oocyte: They provide physical support and nutrients to the developing oocyte.
Hormone production: Granulosa cells are responsible for the production of estrogens, which are crucial for the regulation of the menstrual cycle and the development of secondary sexual characteristics.
Follicular development: They play a role in the maturation of the ovarian follicle, which is necessary for ovulation.

Follicular Development

File:Mature Graffian follicle.jpg

Diagram of a mature Graafian follicle showing granulosa cells.

Granulosa cells undergo several stages of development as the follicle matures:

Primordial follicle: In the earliest stage, granulosa cells are flat and form a single layer around the oocyte.
Primary follicle: The granulosa cells become cuboidal and proliferate to form multiple layers.
Secondary follicle: The granulosa cells continue to proliferate and secrete follicular fluid, forming the antrum.
Graafian follicle: In the mature follicle, granulosa cells form the cumulus oophorus, which supports the oocyte.

Role in Ovulation

Granulosa cells are involved in the process of ovulation. They respond to the surge in luteinizing hormone (LH) by producing enzymes that break down the follicular wall, allowing the release of the oocyte.

Clinical Significance

Granulosa cells are involved in several clinical conditions:

Granulosa cell tumor: A rare type of ovarian tumor that arises from granulosa cells.
Polycystic ovary syndrome (PCOS): A condition characterized by an imbalance in sex hormones, affecting granulosa cell function.

Related pages

Diagram of a section through the ovary showing follicles at different stages of development.

@@ Line 1: / Line 1: @@
-{{Short description|Detailed overview of granulosa cells in the human body}}
+Granulosa cell
-==Granulosa Cells==
+[[File:Pig_oocyte_dapi_4.jpg|thumb|right|Micrograph of a pig oocyte surrounded by granulosa cells.]]
-Granulosa cells are a type of somatic cell found within the [[ovarian follicle]]s of the female reproductive system. These cells play a crucial role in the development and function of the [[ovary]], particularly in the processes of [[oogenesis]] and [[folliculogenesis]].
-==Structure and Location==
+Granulosa cells are somatic cells of the sex cord that are closely associated with the developing female gamete, the oocyte, within the ovary. These cells play a crucial role in the development and function of the ovarian follicle, as well as in the production of sex steroids.
-Granulosa cells are located in the [[ovarian cortex]], surrounding the developing [[oocyte]] within the [[follicle]]. They form multiple layers around the oocyte, starting as a single layer in primordial follicles and proliferating to form multiple layers in more mature follicles, such as the [[antral follicle]].
-[[File:Ovary_anatomy.png|thumb|right|Diagram of the ovary showing the location of granulosa cells within the follicle.]]
+==Structure==
+Granulosa cells are found in the ovarian follicles, which are the basic units of female reproductive biology. Each follicle contains an oocyte, surrounded by granulosa cells and theca cells. The granulosa cells form several layers around the oocyte and are involved in the formation of the [[zona pellucida]], a glycoprotein layer surrounding the oocyte.
 ==Function==
-Granulosa cells have several key functions:
+Granulosa cells have several important functions:
-* '''Support of Oocyte Development''': Granulosa cells provide physical support and nutrients to the developing oocyte. They are involved in the formation of the [[zona pellucida]], a glycoprotein layer surrounding the oocyte.
+* '''Support of the oocyte''': They provide physical support and nutrients to the developing oocyte.
+* '''Hormone production''': Granulosa cells are responsible for the production of [[estrogen]]s, which are crucial for the regulation of the menstrual cycle and the development of secondary sexual characteristics.
+* '''Follicular development''': They play a role in the maturation of the ovarian follicle, which is necessary for ovulation.
-* '''Hormone Production''': These cells are responsible for the production of [[estrogen]]s, particularly [[estradiol]], through the aromatization of androgens. This process is crucial for the regulation of the menstrual cycle and the development of secondary sexual characteristics.
+==Follicular Development==
+[[File:mature_Graffian_follicle.jpg|thumb|left|Diagram of a mature Graafian follicle showing granulosa cells.]]
-* '''Follicular Fluid Secretion''': Granulosa cells secrete follicular fluid, which fills the antrum of the follicle and is essential for follicle expansion and oocyte maturation.
+Granulosa cells undergo several stages of development as the follicle matures:
-* '''Regulation of Follicle Maturation''': Through the production of [[inhibin]] and [[activin]], granulosa cells regulate the secretion of [[follicle-stimulating hormone]] (FSH) from the [[pituitary gland]], thus controlling follicle maturation.
+* '''Primordial follicle''': In the earliest stage, granulosa cells are flat and form a single layer around the oocyte.
+* '''Primary follicle''': The granulosa cells become cuboidal and proliferate to form multiple layers.
+* '''Secondary follicle''': The granulosa cells continue to proliferate and secrete follicular fluid, forming the antrum.
+* '''Graafian follicle''': In the mature follicle, granulosa cells form the cumulus oophorus, which supports the oocyte.
-==Role in the Menstrual Cycle==
+==Role in Ovulation==
-During the menstrual cycle, granulosa cells undergo significant changes. In the follicular phase, they proliferate and increase in number, contributing to the growth of the follicle. As the follicle matures, granulosa cells increase their production of estradiol, leading to the [[LH surge]] that triggers [[ovulation]]. After ovulation, the remaining granulosa cells transform into [[luteal cells]] and form the [[corpus luteum]], which secretes [[progesterone]] to maintain the [[endometrium]] for potential [[implantation]].
+Granulosa cells are involved in the process of ovulation. They respond to the surge in [[luteinizing hormone]] (LH) by producing enzymes that break down the follicular wall, allowing the release of the oocyte.
 ==Clinical Significance==
 Granulosa cells are involved in several clinical conditions:
-* '''Granulosa Cell Tumors''': These are rare ovarian tumors that arise from granulosa cells. They can produce estrogen, leading to symptoms such as abnormal uterine bleeding.
+* '''Granulosa cell tumor''': A rare type of ovarian tumor that arises from granulosa cells.
+* '''Polycystic ovary syndrome (PCOS)''': A condition characterized by an imbalance in sex hormones, affecting granulosa cell function.
-* '''Polycystic Ovary Syndrome (PCOS)''': In PCOS, the function of granulosa cells is often disrupted, leading to anovulation and hormonal imbalances.
+==Related pages==
-* '''Infertility''': Dysfunctional granulosa cells can contribute to infertility due to impaired follicle development and hormone production.
-==Related Pages==
 * [[Ovarian follicle]]
 * [[Oocyte]]
 * [[Estrogen]]
-* [[Follicle-stimulating hormone]]
 * [[Luteinizing hormone]]
-* [[Corpus luteum]]
+[[File:Gray1164.png|thumb|right|Diagram of a section through the ovary showing follicles at different stages of development.]]
 [[Category:Cell biology]]
 [[Category:Reproductive system]]
-[[Category:Endocrinology]]