Theca

(redirected from Thecal cells)
Also found in: Dictionary, Thesaurus, Medical.
Related to Thecal cells: Granulosa cells

theca

[′thē·kə]
(anatomy)
The sheath of dura mater which covers the spinal cord.
(botany)
A moss capsule.
A pollen sac.
(histology)
The layer of stroma surrounding a Graafian follicle.
(invertebrate zoology)
The test of a testate protozoan or a rotifer.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Theca

 

various types of sheath in animals and plants:

(1) A cell wall in certain amoebae (thecamoebae).

(2) A chitinoid membrane in hydroid polyps; hence the division into the suborders Thecaphora and Athecata.

(3) The connective tissue surrounding ovarian follicles in vertebrates (theca folliculi).

(4) A tooth socket in the jawbone of mammals and crocodiles.

(5) A capsule for spores in mosses.

(6) The valve of a silicified test; in diatoms, the upper half is the epitheca and the lower half, the hypotheca.

(7) The pollen sac of an anther in angiosperms.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
The ovary remains the primary source of hyperandrogenism in women with PCOS which is mainly attributed to thecal cell hyperplasia leading to intense ovarian steroidogenesis.
Ebola Virus GP and VP40 Localization in Infected Cell Types of Nonhuman Primates and Guinea Pigs(*) VP40 GP Cell Type ISH IHC ISH IHC Macrophages and monocytes + + + - Fibroblasts + + + + FRC + + + + Epithelia([dagger]) + + + + Ovarian thecal cells + + + + Hepatocytes([double dagger]) + + + + Adrenal cortical cells([double dagger]) + + + + Renal PCTs - + - - Vero E6 cells([sections]) ND + ND - 293 cells([sections]) ND + ND - (*) ISH indicates in situ hybridization; IHC, immunohistochemistry; FRC, fibroblastic reticular cells; PCT, proximal convoluted tubule; ND,in situ hybridization not done on these samples; +, cell type was consistently labeled by the stated method; -, cell type was consistently unlabeled.
The TGF-[beta] superfamily factors, in particular GDF9 and BMP15, play a critical role in ovarian architecture and fertility, being essential for the proper follicular growth and development, as well as for the formation, growth and function of granulosa and thecal cells. Such factors have as their main target the granulosa cells, and from their ability of functional modulation of these somatic cells, play a critical role in oocyte maturation and training process.
Loosely organized layers of spindle-shaped cells develop around the layer of granulosa cells and become known as thecal cells. Unlike the granulosa cell layer, the layer of thecal cells becomes richly supplied with capillaries.
They may contain granulosa cells, thecal cells, Sertoli cells, or fibroblasts of gonadal stromal origin.
Notably, NGF activation of TrkA in cultured thecal cells is reported to be involved in the disruption of gap junctions (Mayerhofer, 1996).
Female fertility depends on the supply and maturation of the ovarian germ cells, i.e., the oocytes and the differentiation and proliferation of ovarian somatic cells, or granulosa and thecal cells (28).
In addition to changing the morphology of the granulosa and thecal cells, the LH surge induces a remarkable reorganization of follicular tissue.