Immunity

1. First Line of Defense

1.1. Unbroken skin

1.2. Mucosal Membrane

1.3. Saliva & Sweat

1.4. Stomach Acid

2. Second Line of Defense

2.1. Natural Immunity (Innate)

2.1.1. Cellular

2.1.1.1. Mast cells, Neutrophils, macrophages

2.1.1.1.1. Macrophages and Monocytes

2.1.2. Humoral

2.1.2.1. Complement, Lysozyme, Interferon

2.2. PAMPS

2.2.1. Toll-like receptors are a set of transmembrane receptors that recognize different types of PAMPS. Found on Macrophages, dendritic cells, and epithelial cells.

3. Third Line of Defense

3.1. Adaptive Immunity

3.1.1. Specificity and Memory

3.1.1.1. Cellular

3.1.1.1.1. T Lymphocytes

3.1.1.2. Humoral

3.1.1.2.1. Antibodies and Cytokines

3.1.1.3. B Lymphocytes

3.1.1.3.1. Mature in the bone marrow

3.1.1.3.2. Express CD 19 as a cell surface marker

3.1.1.3.3. Total number remains unchanged with increasing age.

3.1.1.4. Plasma Cells

3.1.1.4.1. Arise at the end stage of B-Cell differentiation.