9700 · 11.1
The immune system
A comprehensive guide to the Cambridge 9700 syllabus on the immune system (11.1). This lesson covers non-specific and specific immunity, the roles of B and T lymphocytes, antibody action, and vaccination, complete with worked examples and flashcards to ensure full understanding.
Need to know
What you need to know
- Non-specific immunity is immediate and general, involving barriers and phagocytosis.
- Specific immunity is targeted, involves lymphocytes (B and T cells), and creates immunological memory.
- Helper T-cells are central coordinators, releasing cytokines to activate B-cells and cytotoxic T-cells.
- Cytotoxic T-cells destroy infected host cells via perforin.
- B-cells undergo clonal selection and expansion, differentiating into plasma cells (to make antibodies) and memory cells.
- Antibodies are proteins that neutralise pathogens via agglutination, opsonisation, and neutralisation.
- The secondary immune response is faster and stronger than the primary response due to memory cells.
- Vaccination induces artificial active immunity, leading to the formation of memory cells and long-term protection.
Explanation
The immune system
- Non-specific immunity is immediate and general, involving barriers and phagocytosis.
- Specific immunity is targeted, involves lymphocytes (B and T cells), and creates immunological memory.
- Helper T-cells are central coordinators, releasing cytokines to activate B-cells and cytotoxic T-cells.
- Cytotoxic T-cells destroy infected host cells via perforin.