What is theca interna?
Theca interna cells express receptors for luteinizing hormone (LH) to produce androstenedione, which via a few steps, gives the granulosa the precursor for estrogen manufacturing. Theca lutein cells secrete androgens and progesterone. Theca lutein cells are also known as small luteal cells.
Where are theca interna cells found?
ovarian follicles
The theca folliculi comprise a layer of the ovarian follicles. They appear as the follicles become secondary follicles. The theca are divided into two layers, the theca interna and the theca externa. Theca cells are a group of endocrine cells in the ovary made up of connective tissue surrounding the follicle.
What is theca externa layer?
The theca externa is a connective tissue layer derived from fibroblast-like cells that produce extracellular matrix factors, such as collagen. The theca interna and externa also contain a rich supply of blood vessels called the vascular tissue that brings nutrients, oxygen, and immune cells to the growing follicles.
Which cells does theca layer over graafian follicle?
The Graafian Follicle The graafian, or mature, follicle may be up to 2.5 cm in diameter at the time of ovulation, and it protrudes from the surface of the ovary. An outer layer of theca cells and granulosa cells surround a vesicle containing fluid and the oocyte.
What is theca interna and externa?
The theca interna contains the endocrine cells that produce the steroid hormones. The theca externa is a connective tissue layer derived from fibroblast-like cells that produce extracellular matrix factors, such as collagen.
What is the function of theca interna?
Theca cells function in a diverse range of necessary roles during folliculogenesis; to synthesize androgens, provide crosstalk with granulosa cells and oocytes during development, and provide structural support of the growing follicle as it progresses through the developmental stages to produce a mature and …
What are theca cells and granulosa cells?
The granulosa and theca cells are a site of action for the gonadotropins and a site for production of steroid hormones. The theca cells respond to luteinizing hormone (LH) and produce androgens, as well as progesterone in the pre-ovulatory large follicles (Magoffin, 2005; Wickenheisser et al., 2006).
Is theca interna vascular?
The theca interna and externa also contain a rich supply of blood vessels called the vascular tissue that brings nutrients, oxygen, and immune cells to the growing follicles.
Do theca interna cells produce testosterone?
Estradiol-17Ξ² In the chicken ovary, the granulosa cells produce progesterone and the thecal cells convert them into testosterone and E2 [8].
Where are theca and granulosa cells?
Granulosa lutein cells are closest to the central connective tissue core of the corpus luteum and produce progesterone. Theca lutein cells are smaller cells than the former with dark-staining nuclei. These cells produce estrogen and are located peripherally between the folds of the granulosa lutein cells.
Is theca interna fibrous?
Definition of the Ovarian Follicular Theca Layer The theca interna contains theca endocrine cells; the externa is a fibrous, connective tissue layer derived from fibroblastlike cells.
What is theca cell and granulosa cell?
The theca cells respond to luteinizing hormone (LH) and produce androgens, as well as progesterone in the pre-ovulatory large follicles (Magoffin, 2005; Wickenheisser et al., 2006). The granulosa cells respond to follicle stimulating hormone (FSH) and produce estrogen.
What kind of cells are in the theca interna?
The theca interna contains theca endocrine cells; the externa is a fibrous, connective tissue layer derived from fibroblastlike cells. The theca interna/externa also contains vascular tissue, immune cells, and matrix factors (Fig. 1).
Where are the theca cells located in the ovary?
The theca folliculi comprise a layer of the ovarian follicles. They appear as the follicles become secondary follicles. The theca are divided into two layers, the theca interna and the theca externa. Theca cells are a group of endocrine cells in the ovary made up of connective tissue surrounding the follicle.
What happens to the theca cells during development?
During development, the majority of follicles undergo atresia, and the theca cells are often the final follicular cell type to die. For those follicles that do ovulate, the theca cells then undergo hormone-dependent differentiation into luteinized thecal cells of the corpus luteum.
What are the functions of theca cells in the follicle?
Theca cells are responsible for synthesizing androgens, providing signal transduction between granulosa cells and oocytes during development by the establishment of a vascular system, providing nutrients, and providing structure and support to the follicle as it matures.