MRCP UK EXAMINATIONS

Detailed explanation-1: -Opsonised bacteria are fixed to the surface of the phagocytic cells which contain receptors for IgG and C3. Following immune adherence ingestion of bacteria involves invagination of the plasmalemmal membrane. This process utilises ATP and a re-arrangement of lipids occurs during formation of the phagocytic vacuole.

Detailed explanation-2: -Phagocytosis. The ability of neutrophils to ingest and subsequently kill invading microbes is essential for the maintenance of host health. Neutrophils remove bacterial and fungal pathogens through a process known as phagocytosis.

Detailed explanation-3: -Phagocytosis consists in recognition and ingestion of particles larger than 0.5 m into a plasma membrane derived vesicle, known as phagosome. Phagocytes can ingest microbial pathogens, but importantly also apoptotic cells.

Detailed explanation-4: -The uptake of macromolecules and larger energy-rich particles into the cell is known as phagocytosis. Phagocytosed material is enzymatically degraded in membrane bound vesicles of the endosome/lysosome system (intracellular digestion).

Detailed explanation-5: -Neutrophils mainly kill pathogens through phagocytosis, a process in which bacteria are engulfed into intracellular vesicles called phagosomes. The phagosomes then mature into lytic vesicles: they become filled with antimicrobial substances stored into cytoplasmic granules and with toxic reactive oxygen species.