Phagocytosis is a cellular process in which certain cells, known as phagocytes, engulf and digest large particles, such as bacteria, dead cells, and other debris. This process involves the extension of the cell membrane around the target particle, forming a vesicle called a phagosome. The phagosome then fuses with lysosomes, which contain digestive enzymes that break down the engulfed material. Phagocytosis is a crucial mechanism of the immune system, helping to protect the body from infections and maintain tissue homeostasis by clearing away cellular debris and pathogens.
What is phagocytosis?
Phagocytosis is a cellular process in which certain cells, known as phagocytes, engulf and digest large particles, such as bacteria and dead cells.
Which cells are primarily responsible for phagocytosis in the immune system?
The primary cells responsible for phagocytosis in the immune system are macrophages and neutrophils.
What is the first step in the phagocytosis process?
The first step in phagocytosis is the recognition and binding of the target particle to the surface receptors of the phagocyte.
What structure is formed when a phagocyte engulfs a particle?
When a phagocyte engulfs a particle, it forms a vesicle called a phagosome.
What happens to the phagosome after it is formed?
The phagosome fuses with lysosomes to form a phagolysosome, where digestive enzymes break down the engulfed material.
What is the primary function of phagocytosis?
a) To produce energy
b) To engulf and digest large particles
c) To synthesize proteins
d) To transport nutrients
Answer: b) To engulf and digest large particles
Which type of cells are primarily involved in phagocytosis?
a) Erythrocytes
b) Neurons
c) Phagocytes
d) Muscle cells
Answer: c) Phagocytes
What structure is formed when a phagocyte engulfs a particle?
a) Lysosome
b) Phagosome
c) Ribosome
d) Endosome
Answer: b) Phagosome
What happens to the phagosome after it is formed?
a) It is expelled from the cell
b) It fuses with a lysosome
c) It divides into two
d) It remains unchanged
Answer: b) It fuses with a lysosome
What role do opsonins play in phagocytosis?
a) They block phagocytosis
b) They enhance recognition of pathogens
c) They digest engulfed materials
d) They form phagosomes
Answer: b) They enhance recognition of pathogens