(39) GCSE Biology Revision "The Immune System"

Overview of the Immune System

• Function: Protects the body from pathogens (bacteria, viruses, etc.) when nonspecific defenses are breached.

Immune System Functions

1. Destroying Pathogens

• Pathogen Integration: Pathogens can enter the body through breaks in the skin and multiply, releasing toxins that harm healthy tissues.

• Role of White Blood Cells:

  • Ingestion of Pathogens:

    • White blood cells can ingest and destroy pathogens through a process called phagocytosis.

    • Phagocytosis Process:

      • White blood cells detect chemicals from pathogens and move towards them.

      • They ingest (note: use 'ingest' instead of 'eat') pathogens and utilize enzymes to destroy them.

2. Antibody Production

• Antibodies:

  • Produced by white blood cells; these are specific protein molecules.

  • Function of Antibodies:

    • They attach to pathogens, marking them for destruction.

    • Specificity: Antibodies are highly specific for each pathogen; e.g., antibodies for measles don't work against other pathogens.

    • Longevity: Antibodies can linger in the bloodstream, offering protection against future infections from the same pathogen.

3. Antitoxins Production

• Antitoxins:

  • Produced by white blood cells to neutralize toxins released by certain bacteria.

  • Antitoxins stick to toxins, preventing them from damaging cells in the body.

Conclusion

• The immune system serves as a critical defense against disease by utilizing white blood cells to identify and destroy pathogens, produce specific antibodies, and generate antitoxins against harmful toxins.