What is the meaning of paracellular?
(păr″ă-sĕl′ū-lĭr) [″ + ″] Pertaining to pathways or junctions between or around cells. It is used for ions that pass through an epithelial membrane without entering its cells.
What is paracellular flow?
Paracellular transport refers to the transfer of substances across an epithelium by passing through the intercellular space between the cells. It is in contrast to transcellular transport, where the substances travel through the cell, passing through both the apical membrane and basolateral membrane.
What is paracellular diffusion?
What is Paracellular Diffusion? Paracellular transport is the movement of substances across the epithelium through the intercellular space between the cells. This movement is a type of passive diffusion. Therefore, there is no requirement of energy as the diffusion occurs through a concentration gradient.
How does paracellular transport occur?
Paracellular transport refers to transport that occurs in between cells, passing through an intercellular shunt pathway. Paracellular transport appears to be exclusively passive and downhill, occurring by diffusion or convection, and driven by existing transepithelial gradients.
Where does Paracellular transport take place?
Paracellular transport is a passive transport process that results in the transport of substances across an epithelium by passing through the intercellular spaces in between epithelial cells.
What is Paracellular absorption?
Paracellular absorption involves movement of solutes through a restrictive aqueous channel in the tight junctions of adjoining cells [18] by diffusion or by the process of solvent drag [19].
What is Paracellular permeability?
Paracellular permeability is related to the pores in the epithelial TJ determining a high-capacity, size-restricted pathway and a low-capacity, size-independent (or less restrictive) pathway that might be due to fixed (e.g., tricellular junctions, larger pores) or transient breaks (e.g., apoptosis) in the epithelial …
What is paracellular absorption?
What is reabsorbed by the Paracellular route?
The paracellular pathway through the tight junction provides an important route for chloride reabsorption in the collecting duct of the kidney.
Where are enterocytes found in the body?
Enterocytes, or intestinal absorptive cells, are simple columnar epithelial cells which line the inner surface of the small and large intestines.
What is tight junction simple?
Tight junctions are intercellular adhesion complexes in epithelia and endothelia that control paracellular permeability. This paracellular diffusion barrier is semipermeable: it is size- and charge-selective. Paracellular ion permeability at tight junctions is largely determined by their claudin composition.
How tight junction is formed?
The epithelial tissue is held intact by the formation of tight junctions between cells. The basic functional units that form adhesive contacts across cells are the tight junction strands, which are composed of transmembrane proteins such as claudin, occludin and tricellulin.
What are enterocytes?
Enterocytes, or intestinal absorptive cells, are simple columnar epithelial cells which line the inner surface of the small and large intestines. A glycocalyx surface coat contains digestive enzymes. Microvilli on the apical surface increase its surface area.