Theca

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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 ?
A characteristic feature of some gothograptids is the presence of singular hoods, developed on the genicular list of thecal apertures.
Large masses can cause effacement of the thecal sac and can displace and compress the spinal cord.
To conclude, thecal compression is considered the major contributor to block ascent with EVE along with an additional dose-dependent drug effect.
Involvement of nerve growth factor in the ovulatory cascade: trkA receptor activation inhibits gap junctional communication between thecal cells.
On thecal morphology of dinoflagellates with special emphasis on circular (sic) and sulcal plates.
Troglitazone, an insulin-sensitizing thiazolidinedione, represses combined stimulation by LH and insulin of de novo androgen biosynthesis by thecal cells in vitro.
The goal of decompressive laminectomy is to relieve pressure on the thecal sac and exiting nerve roots, while preventing instability.
Metabolic regulation of androgen production by human thecal cells in vitro.
Most of these cell types also contained GP antigen as well, including hepatocytes; adrenal cortical cells; the epithelium of the tongue, tonsil, esophagus, and urinary bladder; ovarian thecal cells; fibroblasts of many tissues; fibroblastic reticular cells of the lymph nodes and tonsils; and the fibroblastic reticulum of the liver and adrenal cortex (Figure 1).
A CT scan performed on November 29, 1993, revealed disc degeneration and a large, extradural defect compressing the thecal sac.
com DOWNTOWN LAS VEGAS California Hotel and Casino thecal.