Theca

Noun

1. Any of several external cases or sheaths. The pollen-producing organ usually found in pairs and forming an anther. The theca folliculi: the twin layers of cells surrounding the basal lamina of an ovarian follicle. The thecal sac: the portion of the dura mater that surrounds the spinal cord and the cauda equina. The membrane complex enveloping the cells of certain plankton including diatoms and dinoflagellates. The calcareous wall of a corallite, the exoskeleton of a coral polyp. A sporangium: a spore case.
2. The pollen-producing organ usually found in pairs and forming an anther.
3. The theca folliculi: the twin layers of cells surrounding the basal lamina of an ovarian follicle.
4. The thecal sac: the portion of the dura mater that surrounds the spinal cord and the cauda equina.
5. The membrane complex enveloping the cells of certain plankton including diatoms and dinoflagellates.