① Lymphocyte: a. T-lymphocytes: cytotoxic T cell: Tc C- kill the tumor cell, virus infective cell and foreign cell helper T cell: Th C- promotes activity of BLC and Tc C suppressor T cell: Ts C –regulate the function of BLC and TC
1.General feature: (1) contain more cells and less extracellular ground substance (2) Polarisaton: ---free outer surface: face air or other things ---basal surface: face underlying CT, havebasement membrane (3) Avascularity,but innervation: ---no blood vessels ---rich in nerve terminals