Defensive cells are phagocytic cells (neutrophils and macrophages), eosinophils, natural killer cells
Eosinophils: attack pathogens that are too large for phagocytosis, such as parasiticworms
Macrophages: consume pathogens and clean up debris
Natural killer cells are a type of white blood cell that can kill infected or cancerous cells
Interferons are small proteins that slow viral reproduction
Interferons attract macrophages and natural killer cells that destroy infected cells; stimulate neighboring cells to make proteins that prevent the viruses from replicating
The complement system assists other defensive mechanisms; is the group of proteins that enhances both non-specific and specific defense mechanisms; destroys pathogens, enhances phagocytosis, stimulates inflammation
Inflammation destroys invaders and helps repair and restore damaged tissue
There are 4 signs of inflammation: redness, heat, swelling, pain
Fever is an abnormally high body temperature caused by pyrogens (lipopolysaccharides)
A mild or moderate fever helps fight bacterial infection
A very high temperature over 105F or 40.6C is DANGEROUS