Section 5: Phagocytosis & Inflammation

What is phagocytosis?

Form of endocytosis where cells ingest large particles into phagosomes, degraded by lysosomes.

Name the professional phagocytes.

Macrophages, neutrophils, dendritic cells

List the 4 steps of phagocytosis.

1) Chemotaxis & adhesion, 2) Engulfment & phagosome formation, 3) Phagolysosome formation, 4) Killing & destruction

What are the 5 cardinal signs of inflammation?

Rubor (redness), calor (warmth), dolor (pain), tumor (swelling), functio laesa (altered function).

What is diapedesis?

WBCs passing through blood vessels to migrate to tissues.

What is pus composed of?

Dead/dying WBCs (mostly neutrophils), dead tissue, dead microbes.

What are pyogenic microorganisms?

Pus-forming bacteria (example: Streptococcus, Staphylococcus).

What is the final step of inflammation?

Resolution (complete repair or scar formation).

What is a pyrogen?

Substance that resets the body’s thermostat higher, causing fever.

Give an example of an endogenous pyrogen.

Cytokines released during phagocytosis.

Give an example of an exogenous pyrogen.

Viruses, bacteria, endotoxins, vaccines.

List 3 benefits of fever.

Inhibits temp-sensitive microbes, reduces iron availability for bacteria, increases metabolism & immune reactions.