White blood cells (WBC)

Phagocytes (Left branch):

1) Neutrophil

• Engulf through phagocytosis then die shortly after forming pus

2) Monocyte

Mature in the tissues to form:

1. Macrophages

• Accumulate and reside in organs
• Perform antigen presentation

2. Dendritic cells

• Perform antigen presentation

Lymphocytes (Right branch):

1) T cells

Involved in the cell-mediated response can be divided into:

1. Helper

• Activates T+B cells by releasing chemical messengers (cytokins) after binding to antigen.
• Also release toxic chemicals

2. Killer

• Produce toxic chemicals (e.g, hydrogen peroxide) after binding to a pathogen terminating it.

3. Memory

• Long-living cells
• Are the immunological memory
• Can differentiate into T-killer cells if reinfected

2) B cells

Involved in humoral response can be divided into:

1. Plasma

• Produce antibodies specific to the antigens on the pathogen

2. Memory

• Are the immunologial memory
• Can differentiate into B-plasma cells