| impermeable cell junctions | <cell biology> Specialised intercellular junction in which the two plasma membranes are separated by only 1-2nm. Found near the apical surface of cells in simple epithelia, forms a sealing gasket around the cell. Prevents fluid moving through the intercellular gap and the lateral diffusion of intrinsic membrane proteins between apical and baso lateral domains of the plasma membrane. (18 Nov 1997) |
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| impermeable | Not permeable; not permitting the passage of substances (e.g., liquids, gases) or heat through a membrane or other structure. Synonym: impervious. Origin: L. Im-permeabilis, not to be passed through (05 Mar 2000) |
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| gap junctions | Connections between cells which allow passage of small molecules and electric current. Gap junctions were first described anatomically as regions of close apposition between cells with a narrow (1-2 nm) gap between cell membranes. The variety in the properties of gap junctions is reflected in the number of connexins, the family of proteins which form the junctions. (12 Dec 1998) |
| intercellular junctions | Direct contact of a cell with a neighboring cell. most such junctions are too small to be resolved by light microscopy, but they can be visualised by conventional or freeze-fracture electron microscopy, both of which show that the interacting cell membrane and often the underlying cytoplasm and the intervening extracellular space are highly specialised in these regions. (12 Dec 1998) |
| tight junctions | Cell-cell junctions that seal adjacent epithelial cells together, preventing the passage of most dissolved molecules from one side of the epithelial sheet to the other. (alberts et al., molecular biology of the cell, 2nd ed, pg-22) (12 Dec 1998) |
| junctions | See: adherens junction, desmosome, gap junction, zonula occludens. (18 Nov 1997) |
| T-cell-rich, B-cell lymphoma | <tumour> A B-cell lymphoma in which more than 90% of the cells are of T-cell origin, masking the large cells that form the neoplastic B-cell component. See: adult T-cell lymphoma. (05 Mar 2000) |
| absorption cell | A small glass chamber with parallel sides, in which absorption spectra of solutions can be obtained. (05 Mar 2000) |
| acid cell | One of the cell's of the gastric glands; it lies upon the basement membrane, covered by the chief cell's, and secretes hydrochloric acid that reaches the lumen of the gland through fine intracellular and intercellular canals (canaliculi). Synonym: acid cell, oxyntic cell. (05 Mar 2000) |
| acidophil cell | A cell whose cytoplasm or its granules stain with acid dyes. (05 Mar 2000) |
| acinar cell | Any secreting cell lining an acinus, especially applied to the cell's of the pancreas that furnish pancreatic juice and enzymes to distinguish them from the cell's of ducts and the islets of Langerhans. Synonym: acinous cell. (05 Mar 2000) |
| acinar cell tumour | A solid and cystic tumour of the pancreas, occurring in young women; tumour cells contain zymogen granules. (05 Mar 2000) |
| acinic cell adenocarcinoma | <tumour> An adenocarcinoma arising from secreting cells of a racemose gland, particularly the salivary glands. Synonym: acinar carcinoma, acinic cell carcinoma, acinose carcinoma, acinous carcinoma. (05 Mar 2000) |
| acinic cell carcinoma | <tumour> An adenocarcinoma arising from secreting cells of a racemose gland, particularly the salivary glands. Synonym: acinar carcinoma, acinic cell carcinoma, acinose carcinoma, acinous carcinoma. (05 Mar 2000) |
| acinous cell | Any secreting cell lining an acinus, especially applied to the cell's of the pancreas that furnish pancreatic juice and enzymes to distinguish them from the cell's of ducts and the islets of Langerhans. Synonym: acinous cell. (05 Mar 2000) |
| acoustic cell | A hair cell of the organ of Corti. (05 Mar 2000) |