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tight junctions formed by the fusion of integral proteins of the lateral cell membranes of adjacent epithelial cells, limiting transepithelial permeability.
Etymology: L, zona, belt, occludere, to close up
a component of the junctional complex between cells in which there is no intercellular space and the plasma membranes of adjacent cells are in direct contact.
zonula(zon'yu-la) [L. zonula, little girdle]
A small zone. Synonym: zonule
The portion of the junctional complex between columnar epithelial cells below the zonula occludens where there is an intercellular space of about 200 A.U. and the cellular membranes are supported by filamentous material.
zonula ciliarisCiliary zonule.
zonula occludensTight junction.
pl. zonulae [L.] zonule.
common component of junctional complexes between epithelial cells; forms an effective barrier between the lumen and connective tissue. Called also tight junction.
suspensory ligament of the lens.
part of the junctional complex of columnar epithelium.