Immune system

1. External barriers

1.1. Skin

1.1.1. Dry and dead cells

1.1.2. Lactic acid

1.1.3. Sweat and Sebum

1.1.4. Good bacteria (Bacterial flora)

1.1.5. Lysozyme

1.2. Mucous membranes

1.2.1. Cilia

1.2.2. Mucus

1.2.2.1. Trapped germs are killed by HCl and Proteolytic enzymes

2. Non-specific internal defenses

2.1. Phagocytosis

2.2. NK cells

2.3. Inflammation

2.4. Fever

3. Specific immune response

3.1. Lymphocytes

3.1.1. B- cells

3.1.1.1. Memory B-cells

3.1.1.2. Plasma cells

3.1.2. T- cells

3.1.2.1. Cytotoxic T- cells

3.1.2.2. Helper T-cells

3.1.2.3. Supressor T-cells

3.1.2.4. Memory T-cells