Theca

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Related to Theca 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.

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 first study by Wood et al (41) on theca cells from PCOS and normal ovary showed differential expression of 346 genes.
2] began to be produced in theca cells, granulosa acting on paracrine manner and is involved in the induction of LH surge before ovulation, and this is motivated by the increased sensitivity to LH in granulosa cells, respectively.
Insulin-sensitizers have a positive effect in PCOS patients through normalization of hyperinsulinaemia that otherwise amplifies the excessive androgen production from the ovary theca cells via CYP17 phosphorylation and lower levels of SHBG.
To collect mural granulosa / theca cell complexes, small (n=10) and large (n=10) antral follicles were isolated from ovaries (n=5) and dissected free from stromal tissue with forceps as described by VAN TOL & BEVERS (1998).
A gel mould shaped like a honeycomb was seeded with theca cells, which grew into a structure 2 millimetres wide.
The number of proliferating and non-proliferating cells was determined for granulosa and theca cells of secondary (n=99 total) and antral (n=45 total) follicles.
2000), it also inhibits androgen production in ovarian theca cells (Schoppee et al.
On the other hand, it is known that apoptosis can occur in at least four different follicular compartments, theca cells, mural cells, cumulus cells and in the oocyte (12) and that ovarian follicles with identical morphology have different apoptosis levels in mural granulosa and cumulus cells (25).
In bovine theca cells, arachidonic acid modulated androstenedione secretion, which suggests an indirect effect of omega-3 fatty acids through the displacement of, or increased competition with, omega-6 fatty acids.
Studies have shown tissue-specific expression of the FSH receptor (FSHR) in granulosa cells and LHR in theca cells of all growing follicles.
Total cellular RNA (tcRNA) was isolated from snap-frozen samples of granulosa and theca cells from preovulatory (-4 mm) follicles that were obtained at 0, 2, 4, 8, 12, 24, and 48 h after hCG-treatment.