nounthecae

• 1Anatomy
  The loose sheath enclosing the spinal cord.

  ‘The vertebral foramen houses the theca and spinal nerves.’

  More example sentences

  • ‘The theca contains the cauda equina or nerve roots.’

  1. 1.1The outer layer of cells of a Graafian follicle.
     ‘The term ‘follicle complex’ has been proposed to include the follicle, basement membrane, and the theca, including its blood vessels.’
     More example sentences

     • ‘The follicle is surrounded by a theca, derived from the stromal compartment of the ovary and is always separated from this compartment, throughout development and final oocyte maturation, by a basement membrane.’

• 2Zoology
  A cuplike or tubular structure containing a coral polyp.

  ‘It is notable that both specimens also display asymmetry in the overall structure of their thecae.’

  More example sentences

  • ‘In the ‘echinoderm’ reconstruction, the theca lies with the convex side upwards and the appendage is interpreted as an anterior feeding arm.’
  • ‘The theca around the column is smooth, sometimes with weak longitudinal muscles.’
  • ‘Despite its good preservation, this single specimen did not show all aspects of the theca.’
  • ‘Calices and thecae are commonly intact, but typically lack feeding appendages.’

• 3Botany
  Either of the lobes of an anther, each containing two pollen sacs.

  ‘As pollinators removed pollen from the thecae, their walls collapsed and the anthers curled down gradually.’

  More example sentences

  • ‘The percentage of thecae that dehisced longitudinally varied greatly among rice varieties.’
  • ‘Stamens are didynamous, but the yellow anthers occur close together, with their divergent thecae spreading to the outside.’
  • ‘Each sequence of thecae forms a stipe, or branch, and colonies varied in the numbers of stipes that they possessed.’
  • ‘At this stage, at least one theca is already opened, and pollinators are attracted to the flowers.’

  Synonyms

  bag, pouch, bladder, blister