Definition of Theca

1. Noun. A case or sheath especially a pollen sac or moss capsule.

Exact synonyms: Sac
Generic synonyms: Cover, Covering, Natural Covering

2. Noun. Outer sheath of the pupa of certain insects.
Generic synonyms: Case, Sheath

Definition of Theca

1. n. A sheath; a case; as, the theca, or cell, of an anther; the theca, or spore case, of a fungus; the theca of the spinal cord.

Definition of Theca

1. Noun. (biology) Any external case or sheath. ¹

2. Noun. (botany) The pollen producing organ usually found in pairs and forming an anther. ¹

3. Noun. (medicine) The twin layers of cells surrounding the basal lamina of an ovarian follicle ¹

4. Noun. (microbiology planktology) The membrane complex enveloping the cells of certain plankton including diatoms and dinoflagellates ¹

5. Noun. (context: coral science) The calcareous wall of a corallite, the exoskeleton of a coral polyp ¹

¹ Source:

Definition of Theca

1. a protective anatomical covering [n -CAE] : THECAL, THECATE [adj]

Medical Definition of Theca

1. Origin: L, fr. Gr. A case to put anything in. See Tick a cover. 1. A sheath; a case; as, the theca, or cell, of an anther; the theca, or spore case, of a fungus; the theca of the spinal cord. 2. The chitinous cup which protects the hydranths of certain hydroids. The more or less cuplike calicle of a coral. The wall forming a calicle of a coral. Source: Websters Dictionary (01 Mar 1998)

Theca Pictures

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Lexicographical Neighbors of Theca

thebesian circulation
thebesian foramina
thebesian valve
thebesian veins
theca (current term)
theca cells
theca cells of stomach
theca cordis
theca externa
theca folliculi
theca interna
theca interna cone
theca lutein cell
theca vertebralis
thecal abscess

Literary usage of Theca

Below you will find example usage of this term as found in modern and/or classical literature:

1. Scottish Cryptogamic Flora, Or Coloured Figures and Descriptions of by Robert Kaye Greville (1825)
"Plants with young fructification, both nat. size.—The following are all magnified. Fig. 8. theca with the lid. Fig. 4. theca with the half-grown calyptra. ..."

2. Text-book of Botany, Morphological and Physiological by Julius Sachs (1882)
"The latter appears as a column continuous at the base and apex with the wall of the theca. But while in the true Mosses a layer of cells parallel to this ..."

3. On the Manners and Customs of the Ancient Irish by Eugene O'Curry (1873)
"Dr. Ferguson on the antiquity and origin of music in Erinn ; musical canon of the Welsh regulated by Irish harpers about AD 1100; his account of the theca ..."

4. The coral Siderastrea radians and its postlarval development by J[ames] E[dwin] Duerden (1904)
"WALL OR theca. The wall or theca of a simple coral or of a corallite is defined by Vaughan ... 63, the theca is then represented by a narrow, vertical, ..."

5. Gynæcology for Students & Practitioners by Thomas Watts Eden (1920)
"Compound theca-Lutein Cysts are bilateral, thin-walled, multi- locular ovarian ... In general appearance a compound theca-lutein cyst resembles a compound ..."

6. An Introduction to Botany by John Lindley (1832)
"no doubt of the reproductive functions of the contents of what is named the theca or capsule, which is a hollow urn-like body, ..."

7. An introduction to botany by John Lindley (1832)
"This part, so carried upwards, is named the calyptra: if it is torn away equally from its base, so as to hang regularly over the theca, it is said to be ..."

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