Question

A medical student is investigating a response of white blood cells to the bacterial infection. He starts with microscopic investigation of the paronychia in a 55-year-old man. The first thing he sees is a leucocyte propelling the membrane at its leading edge. The student is fascinated and asks you how it happens.

Question
How will you explain phagocytosis in terms of basic active mechanism underlying this first movement of the leading edge?

Traction force
Stall force
Polymerization
Active transport
Adhesion

Answer 1

Phagocytosis is the process by which large particles, such as cells or particles, are engulfed by a cell. In the context of white blood cells responding to a bacterial infection, the leading edge of the white blood cell moves through active transport, polymerization, and adhesion.

Step-by-step explanation:

Phagocytosis is the process by which large particles, such as cells or relatively large particles, are taken in by a cell. In the context of white blood cells responding to a bacterial infection, phagocytosis involves the engulfment of the bacteria by the white blood cell.

When a white blood cell detects a pathogen, it extends pseudopodia (protrusions of the cell membrane) to surround the pathogen. This movement of the leading edge of the white blood cell is achieved through active transport, polymerization of cytoskeletal elements, and adhesion to the pathogen.

Once engulfed, the pathogen is enclosed in a phagosome within the white blood cell. The phagosome fuses with a lysosome, forming a phagolysosome. Within the phagolysosome, the pathogen is destroyed by enzymes and other antimicrobial substances.