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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.
Farlex Partner Medical Dictionary © Farlex 2012
tight junc·tion(tīt jŭngk'shŭn)
An intercellular junction between epithelial cells in which the outer leaflets of lateral cell membranes fuse to form a variable number of parallel interweaving strands that greatly reduce transepithelial permeability to macromolecules, solutes, and water through the paracellular route.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012
Refers to cells in which their membranes are fused rather than separated by a small extracellular space. The movement of substances through that space is restricted. Syn. zonulae occludentes. See blood-brain barrier.
Millodot: Dictionary of Optometry and Visual Science, 7th edition. © 2009 Butterworth-Heinemann