All are involved in phagocytosis except:
Ans: c (Pavementing of cells) Ref: Robbins, 7th ed, p. 59Phagocytosis involves 3 steps; they are:1. Recognition and attachment: Receptor involved are mannose receptors and scavenger receptors. The efficiency is greatly enhanced by opsonisation. Major opsonins are IgG, C,b breakdown products and lectins (MB,)2. Engulfment: Extension of cytoplasm as pseudopods around the particle to be engulfed, resulting in complete enclosure of the particle within the phagosome created by the plasma membrane of the cell.3. Killing and degradation:- by neutrophils and macrophages largely by oxygen dependent mechanisms, producing reactive oxygen metabolites (ROIs)- ROI is produced due to the activation of NADPH oxidase in the lysosome- The H2O2 - MPO- halide system is the most efficient bactericidal system
Recognition and attachment
Engulfment
Pavementing of cells
Killing and degradation
Cellular Pathology