STAGES OF PHAGOCYTOSIS

Summary

Phagocytosis is a crucial immune defense mechanism in multicellular organisms, helping remove pathogens and cell debris. This non-specific process involves specialized cells like neutrophils and macrophages. The stages of phagocytosis include chemotaxis, where phagocytes leave the bloodstream to migrate to affected tissues, followed by the engulfing of pathogens with cytoplasmic extensions called pseudopods. Once the pathogen is enclosed in a phagosome, it fuses with a lysosome to form a phagolysosome, which digests the material. Finally, the digested remnants are expelled from the cell via exocytosis.

Takeaways

• 🛡️ Phagocytosis is an immune defense mechanism in multicellular organisms that removes pathogens and cell debris.
• 🔄 It is a non-specific defense mechanism involving specialized cells like neutrophils and macrophages.
• 📍 Phagocytosis involves multiple stages, starting with the chemotaxis of phagocytic cells to the injury site.
• 🚶 Chemotaxis is the process where phagocytes leave the bloodstream and migrate to affected tissues.
• 🔗 Phagocytes bind to the surface of the pathogen during the initial phase of phagocytosis.
• 🦠 Cytoplasmic extensions called pseudopods form around the pathogen during engulfment.
• 🤝 Pseudopods fuse at the distal end to form a phagosome, which encapsulates the pathogen.
• 🧬 A phagolysosome is formed when the phagosome fuses with a lysosome containing degradative enzymes.
• 🧪 The enzymes inside the lysosome break down the pathogen or debris within the phagolysosome.
• 🚪 The digested material is eliminated from the phagocyte through exocytosis, completing the process.

Q & A

What is phagocytosis in multicellular organisms?

Phagocytosis is an immune defense mechanism used to remove pathogens and cell debris in multicellular organisms.

Is phagocytosis a specific or non-specific defense mechanism?

Phagocytosis is a non-specific defense mechanism.

Which specialized cells are involved in phagocytosis?

Specialized cells such as neutrophils and macrophages are involved in phagocytosis.

What is chemotaxis in the context of phagocytosis?

Chemotaxis is the process by which phagocytic cells move toward the site of injury or infection.

How do phagocytes migrate to the affected tissues?

Phagocytes leave the bloodstream and migrate to the affected tissues through the process of chemotaxis.

What happens after the phagocytes reach the pathogen?

The phagocytes bind to the surface of the pathogen.

What role do pseudopods play in phagocytosis?

Cytoplasmic extensions called pseudopods form and surround the pathogen, eventually fusing to engulf it.

What is a phagosome?

A phagosome is formed when pseudopods fuse at the distal end, surrounding the pathogen.

How is a phagolysosome formed?

A phagolysosome is formed by the fusion of a phagosome with a lysosome, which contains degradative enzymes.

How is the digested material eliminated from the phagocyte?

The digested material is eliminated from the phagocyte through the process of exocytosis.