Myeloid cells

What are the cellular components that make up the myeloid cells?

neutrophils, eosinophils, basophils, monocytes, macrophages, and NK cells (participate in innate response)

What are some characteristics of neutrophils?

• defend against bacteria and fungi

• localized inflammation prolonged through cytokines

• contains granules with enzymes

• usually the first leukocyte to arrive at site of injury

• move through blood vessels (diapedesis)

What does a neutrophil look like?

Cytoplasm contains purple granules, nucleus is banded or segmented

What are some characteristics of eosinophils?

• inc. during allergies and parasitic infections

• usually suppress excess inflammation

• contains granules

What does an eosinophil look like?

Pinker granules within cytoplasm, bigger than the ones in neutrophils

What are some characteristics of basophils?

• regulate acute hypersensitivity (IgE binds to mast cells!)

• granulated with heparin and histamine that:

  • inc. vascular permeability

  • muscle spasms

  • vasodilation

• vast amounts are produced during anaphylactic shock

What do basophils look like?

Very dark purple granules

What are some characteristics of monocytes and macrophages?

• ingest and kill intracellular and extracellular pathogens

• proteolytic enzymes on their surface suppress tumor growth

• present antigens to the adaptive immune system

• secrete cytokines

What does a monocyte look like?

a bi-lobed nucleus with purple cytoplasm

What does an activated monocyte, or macrophage, look like?

Lighter blue cytoplasm with vacuoles touching the nucleus (engulfment of material)

List the steps of phagocytosis.

1. Chemotaxis towards microbe

2. Ingestion of microbe

3. Engulfment into a phagosome within the cell

4. Fusion of a lysosome with the phagosome, producing a phagolysosome

5. digestion of the contents via enzymes

6. Residual body formation housing undigested material

7. Discharge from the cell