CAS BI 315 Lecture Notes - Lecture 4: Nephron, Active Transport, Smooth Muscle Tissue
Document Summary
Tight junctions: link cells together to prevent leakage of ecm material between the cells. Epithelial cells have a polarity defined by the structures they line. Apical (outer) surface: often inside of ta tube or duct being lined by the epithelium( a lumen) Ex- nephrons in kidneys, ducts of glands, walls of the gut. Basolateral(inner) surface of each epithelial cell is usually bound to a special. Tight junctions: close off most of the movement of eater/solute across an epithelial sheet. Transcellular transport: cells that regulate the movement- specific solutes that you want to cross. Paracellular: between epithelial cells can still occur very small molecules and be physiologically important. Interplay between digestive and control systems(endocrine and neural) Composition of feces is not tightly regulated; regulation of excretion mostly occurs during formation of urine. In humans many nutrients can be synthesized/interconverted metabolically(non-essential nutrients) Not all body components can be synthesized by all animals.
