1. Phagocytosis:
* Neutrophils: These are the most abundant white blood cells and are the first responders to infection. They engulf and destroy bacteria through a process called phagocytosis. They release enzymes and toxic chemicals to kill the bacteria inside.
* Macrophages: These are larger, long-lived cells that also engulf and destroy bacteria. They play a key role in cleaning up the debris after an infection and presenting bacterial antigens to other immune cells.
2. Antibody Production:
* B lymphocytes (B cells): These cells produce antibodies, specialized proteins that bind to specific antigens on the surface of bacteria. Antibodies can neutralize bacteria, preventing them from attaching to and infecting cells. They also act as flags, signaling other immune cells to attack the bacteria.
3. Cell-Mediated Immunity:
* T lymphocytes (T cells): These cells directly attack infected cells and bacteria.
* Cytotoxic T cells: They release chemicals that directly kill infected cells and bacteria.
* Helper T cells: They coordinate the immune response by activating other immune cells, like B cells and macrophages.
4. Inflammation:
* White blood cells release signaling molecules called cytokines that trigger inflammation. Inflammation brings more white blood cells to the site of infection and helps isolate the bacteria.
Here's a simplified explanation:
Imagine bacteria as intruders trying to invade your body. White blood cells are like your body's army:
* Neutrophils are the foot soldiers, rushing to the scene and destroying the intruders directly.
* Macrophages are the clean-up crew, removing the debris and reporting the attack.
* B cells are the intelligence agents, producing antibodies (weapons) to target specific intruders.
* T cells are the special forces, targeting infected cells and launching direct attacks.
All of these cells work together to fight off the invaders and protect your body from infection.
