theca

(redirected from Theca cells)
Also found in: Thesaurus, Medical, Legal, Financial, Encyclopedia.
Related to Theca cells: Granulosa cells

the·ca

 (thē′kə)
n. pl. the·cae (-sē′, -kē′)
A case, covering, or sheath, such as the covering of the pollen sacs of an anther or the thick cell wall of certain dinoflagellates.

[Latin thēca, case, receptacle, from Greek thēkē; see dhē- in Indo-European roots.]

the′cal (-kəl) adj.

theca

(ˈθiːkə)
n, pl -cae (-siː)
1. (Botany) botany an enclosing organ, cell, or spore case, esp the capsule of a moss
2. (Zoology) zoology a hard outer covering, such as the cup-shaped container of a coral polyp
[C17: from Latin thēca, from Greek thēkē case; related to Greek tithenai to place]
ˈthecal, ˈthecate adj

the•ca

(ˈθi kə)

n., pl. -cae (-sē).
1. a case or sheath enclosing an animal organ, structure, etc., as the horny covering of an insect pupa.
2. a sac, cell, capsule, or sporangium of a plant or mushroom.
[1655–65; < Latin thēca < Greek thḗkē case, cover, akin to tithénai to place, put]
the′cal, the′cate (-kɪt, -keɪt) adj.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.theca - a case or sheath especially a pollen sac or moss capsule
covering, natural covering, cover - a natural object that covers or envelops; "under a covering of dust"; "the fox was flushed from its cover"
2.theca - outer sheath of the pupa of certain insects
sheath, case - an enveloping structure or covering enclosing an animal or plant organ or part
Translations

the·ca

n. teca, envoltura o capa que actúa esp. como protectora de un órgano.
References in periodicals archive ?
TNF-[alpha] is detected in macrophages, oocytes, granulosa cells, atresia, and theca cells.
In relation, the ES decline in S3 suggested that sub-chronic exposure could disrupt the ES synthesis of theca cells in the ovarian follicles, and the following increase in S4 and S5 confirmed that ES production improved during the recovery period.
However, many studies indicate that GDF9 and BMP15 have critical roles in ovarian architecture of most species and are essential factors for adequate follicular development, interfering considerably in the function, growth and formation of granulosa and theca cells during the growth of the follicle (Vitt and Hsueh, 2001; Otsuka et al.
Angiotensin II reverses the inhibitory action produced by theca cells on bovine oocyte nuclear maturation.
Recent studies showed that hyperandrogenism may also be due to local inflammatory response of ovarian theca cells to reactive oxygen species [33] or to cytokines and chemokines produced by dysfunctional adipose tissue [34].
In women with PCOS, though, the insulin resistance is commonly associated with hyperinsulinemia, which then enhances the production of androgens by the ovarian theca cells, leading to a reduction in circulating levels of SHBG, which leads to increased levels of free testosterone.
DISCUSSION: Sexcord Stromal Tumors: Sex cord-stromal tumors are ovarian tumors that are believed to originate in theca cells, other stromal cells, granulosa cells and their testicular sex cord counterparts, the Sertoli and Leydig cells.
The increase in estrogen in group C compared to group B might be due to increase of LH hormone that leads to increase of its binding with the receptors on theca cells [21].
The main hormone produced from 17[alpha]-hidroxiprogesterone is androstenedione, which can be converted to testosterone by the isoenzyme 17[beta]-hidroxisteroide deidrogenase (HSD17B) in theca cells or to estrone by aromatase (CYP19A1) in granulosa cells.
Theca cells from PCOS ovaries which have been correlated to increased expression and/or activity of CYP17 synthesize increased levels of androgens compared with normal theca cells.
High levels of FSH and LH in the GFF to stimulate follicular development and granulosa cells and theca cells so as to increase the secretion of estrogen as well as LH and FSH stimulates the maturation of acolytes contained within follicles.
Ovarian aromatase expressed in granulosa cells facilitates the conversion of E2 from androgens produced in the theca cells of the antral follicles.