Question

Describe the various defence mechanism which are set off when you cut yourself with a dirty knife.

Answer 1

When you cut yourself with a dirty knife, the body’s defense mechanisms are triggered as follows:

1. Protective Surface Barrier: The skin, which normally acts as a physical and chemical barrier, is breached, allowing microbes to enter the body.
2. Inflammatory Response: The area becomes red, swollen, warm, and painful due to vasodilation and increased permeability of blood vessels caused by the release of histamine and serotonin. This allows plasma, white blood cells, and antibodies to reach the infected site.
3. Phagocytosis: Macrophages and neutrophils engulf and destroy invading pathogens.
4. Activation of the Immune System: Lymphocytes (T-cells and B-cells) recognize the antigens of the pathogens and initiate cellular and humoral immune responses. B-cells produce antibodies specific to the antigen, while T-cells directly attack infected cells or assist other immune cells.
5. Formation of Memory Cells: Some lymphocytes become memory cells, providing immunity against future infections by the same pathogen.