Epithelial Transport

Epithelial Transport

1. Transporters set up multiple gradients which drive paracellular and transcellular movement

   • Oncotic, Chemical and Voltage gradients

2. Epithelia cells isolate the internal environment from the external environment and regulate the movement of solutes and water to and from the body

   • 2 Types of epithelia: absorptive and secretive
   • The assymetrical distribution of carriers in the seperate membranes of the cells allows vectorial transport to take place

3. Tight junctions seperate the basolateral and apical membrane of the cell, hold the cells together and reflect solutes and water

   • TIGHT: prevent significant movement of molecules between cells, high transepithelial potential difference, can withstand high osmotic gradients and found distally
     • LEAKY: prlow transepithelial potential difference