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.
What hormones are made in theca?
Gonadotrophs are stimulated to produce follicle-stimulating hormone (FSH) and luteinizing hormone (LH), which are released into the bloodstream to act upon the ovaries.
Do theca cells secrete progesterone?
Abstract. Female theca and granulosa cells produce estrogens, estrone, estradiol, and estriol in the follicular phase of the menstrual cycle. Corpus luteal cells produce progesterone in the luteal phase of the menstrual cycle.
Do theca interna cells produce testosterone?
In avian species, the granulosa cells produce progesterone (P), but not testosterone (T) or estradiol (E). The theca folliculi in avian species produces T and E and is anatomically comprised of the theca interna and the theca externa. It is not known, however, whether both T and E are produced by the same cell type.
What does theca externa secretes?
The theca externa is a connective tissue layer derived from fibroblast-like cells that produce extracellular matrix factors, such as collagen. … Specifically, GDF9 secreted from the oocyte induces the expression of IHH and DHH in granulosa cells.
Which hormone is most responsible for triggering ovulation?
Luteinizing hormone (LH), the other reproductive pituitary hormone, aids in egg maturation and provides the hormonal trigger to cause ovulation and the release of eggs from the ovary.
Is theca interna vascular?
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. The theca interna/externa also contains vascular tissue, immune cells, and matrix factors (Fig. 1).
Do Leydig cells produce progesterone?
In 2012, the BLTK-1 Leydig cell line was developed from a testicular tumor . These cells retain functional LHCGR-mediated steroidogenesis, producing progesterone, testosterone, and estradiol. … The most important is that the cells produce progesterone rather than testosterone.
Does theca interna secrete estrogen?
No other ovarian cells are known to have FSH receptors. Granulosa cells of the ovulatory follicle are the major and virtually only source of estradiol in the follicular phase of the ovarian cycle and secrete estrogens in response to FSH.
Do theca cells make estrogen?
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 happens to theca cells?
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.
Do primary follicles have theca cells?
The primary follicle develops into a secondary follicle. … The surrounding theca differentiates into two layers: the Theca interna (rounded cells that secrete androgens and follicular fluid) and a more fibrous Theca externa – spindle shaped cells. The androgens are converted into oestrogen by the granulosa cells.
What is theca cells?
Theca cells are the endocrine cells associated with ovarian follicles that play an essential role in fertility by producing the androgen substrate required for ovarian estrogen biosynthesis. Theca cells differentiate from the interfollicular stroma in response to proteins secreted from growing follicles.
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.
When is theca externa formed?
The theca externa is the outer layer of the theca folliculi. It is derived from connective tissue, the cells resembling fibroblasts, and contains abundant collagen. During ovulation, the surge in luteinizing hormone increases cAMP which increases progesterone and PGF2α production.
Where are theca cells located?
Theca cells are endocrine cells located exclusively in the ovary (Erickson, Magoffin, Dyer, & Hofeditz, 1985). The follicle is the basic functional unit of the ovary, containing a single oocyte and granulosa cells enclosed by a basal lamina.