释义 |
DictionarySeejunctiontight junction
tight junction[¦tīt ′jəŋk·shən] (cell and molecular biology) An intercellular junction composed of a series of fusions of the junctional membrane, forming a continuous seal; serves as a selective barrier to small molecules and as a total barrier to large molecules. Also known as impermeable junction; occluding junction; zonula occludens. tight junction
zo·nu·la oc·clu·'denstight junctions formed by the fusion of integral proteins of the lateral cell membranes of adjacent epithelial cells, limiting transepithelial permeability. Synonym(s): impermeable junction, tight junctiontight 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. tight junction 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. |