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.
Interactive stimulation by luteinizing hormone and insulin of the steroidogenic acute regulatory (StAR) protein and 17[alpha]lpha-hydroxylase/17, 20lyase (CYP17) genes in porcine theca cells.
Insulin augmentation of 17[alpha]-hydroxylase activity is mediated by phosphatidyl inositol 3-kinase but not extracellular signal-regulated kinase-1/2 in human ovarian theca cells.
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.
During the follicular phase of ovarian cycle, androstenedione produced by theca cells reaches a level of [10.
Increased LH leads to an increase In androgen production by the theca cells within the ovary.
8) Insulin acts synergistically with LH to enhance androgen production in the ovarian theca cells.
From the preantral stage onward, theca cells differentiate outside the follicles (29).