Different Cells of the Immune System

Natural Killer

Function: Kill virus-infected cells and cancer cells without needing prior exposure

• Part of innate immunity

B-Cells

function: produce antibodies (by becoming plasma cells) to fight specific pathogens

• Part of the Adaptive Immunity

• Antigen-presenting & Cytotoxic (some types)

T-Cells

Function: Coordinate Immunity or kill infected cells

• Part of the Adaptive Immunity

• Antigen-presenting & Cytotoxic (some types)

Megakaryote

Function: Large cell in bone marrow that produces platelets for blood clotting

• part of the Innate Immunity

Mast Cells

Function: Release histamine during allergic reactions and inflammation

• Part of Innate immunity

Myeloblast

Function: Immature bone marrow cell that develops into granulocytes (neutrophils, eosinophils, basophils)

• Part of Innate Immunity

Basophil

Function: White blood cell that releases histamine during allergies and inflammation

• Part of Innate Immunity

• Phagocytic

Neutrophil

Function: First responder to infections; engulfs and destroys bacteria; releases CYTOKINES

• Prominent in inflammation

• Part of Innate immunity

• Phagocytic

Eosinophil

function: Fights parasites and contributes to allergic reactions; releases PROTEASES

• Part of Innate Immunity

• phagocytic and cytotoxic

Monocyte

Travels in the blood and can enter tissues to become a macrophage

• Part of Innate Immunity

• Phagocytic and Antigen-presenting

Macrophage

function: Big eaters that clean up germs and debris

• Part of Innate immunity

• Phagocytic & Antigen-presenting

Dendritic Cells

functions: Capture pathogens and present their antigens to T-cells to activate adaptive immunity

• Innate Immunity → engulf pathogens and collect their antigens

• Adaptive Immunity → present antigens to T-cells to activate a specific immune response

(essentially are messengers between innate and adaptive immunity)

• Antigen-presenting cells

(Usually found in epithelial tissues in contact w/ environment i.e., skin, respiratory, GI tract)

Difference between External, Innate, and Adaptive lines of defense?

External → Keep germs OUT (skin, mucus, barriers)

Innate → Attack ANY germ quickly (NK cells, neutrophils, macrophages, etc.)

Adaptive → Attack SPECIFIC germs and REMEMBER them (B-cells and T-cells)

Cells involved in the External Immunity defense?

None. - uses more mechanisms and organs (such as skin, mucus, tears, saliva, and stomach acid)

Cells involved in the Innate Immunity defense?

Natural Killers, Mast Cells, Basophils, Neutrophils, Eosinophils, Monocytes, Macrophages

Cells involved in Adaptive Immunity defense?

B-Cells and T-Cells