Theca


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Related to Theca: theca folliculi

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.

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.

References in periodicals archive ?
The flavivirus RNA was detected by NS3-based RT-PCR, and the virus was again isolated from theca folliculi.
In recent years, PCOS research has focused on comparative gene expression profiles of different components of ovarian tissue such as theca cells, ovary and oocytes of PCOS and normal women (41-44),.
76) Second, Andreae included axioms from the Confessio in the Theca gladii spiritus (1616), thus linking himself to this second manifesto.
After the theca cells grew into the honeycomb shape, spherical clumps of donated granulosa cells were inserted into the holes of the honeycomb together with human egg cells, known as oocytes.
Pregnancy luteomas are generally thought to arise from nodular hyperplasia of theca interna cells (theca-lutein hyperplasia), (59,67,69) although others (56) have proposed an origin from stromal cells.
The putative ligand-mediated activation of PPAR-[gamma]2 by troglitazone impairs androgen and stimulates progesterone biosynthesis in primary cultures of porcine theca cells (113) by blocking the expression of the cytochrome P450-17-[alpha] hydroxylase/C17-20 lyase gene and CYP protein phosphorylation, which decreases the LH insulin-driven theca cell androgen production.
The labeling index was similar for granulosa and theca cells from secondary or antral follicles (overall 21.
Apptus will now offer companies using FAST a safe passage to their own platform Theca, which today is used by many of the major online directories in Europe.
37-38) Insulin also works with luteinizing hormone (LH) to increase androgen production in the ovarian theca cells.
Apelin and APJ receptor expression in granulosa and theca cells during different stages of follicular development in the bovine ovary: Involvement of apoptosis and hormonal regulation.
They constitute about 5% to 8% of all malignant ovarian neoplasm and include granulosa cell tumor (arise from primitive sex cords) and Sertoli-Leydig cell tumor (arise from theca and Leydig cells).
Increase in NEFA concentration during NEB has an inhibitory effect on proliferation of theca and granulosa cells, negatively influencing folliculogenesis during the early post-partum period in high-yielding dairy cows (Vanholder et al.