Epidemiology
Total number of existing cases at a given time
Prevalence
Transmission through physical contact
Contact transmission
“First line of defense against pathogens
Physical defenses
First responder white blood cells that form pus
Neutrophils
Process of engulfing pathogens
Phagocytosis
Number of new cases over a period of time
Incidence
Transmission through food, water, or air
Vehicle transmission
Moves mucus and trapped microbes out of lungs
Mucociliary escalator
Cells that target parasites and allergic responses
Eosinophils
Vesicle formed after engulfment
Phagosome
A disease constantly present in a population
Endemic
Transmission through a living organism
Vector transmission
Beneficial microbes that prevent pathogen growth
Microbiome
Cells that release histamine and contribute to inflammation
Basophils
Structure formed when phagosome fuses with lysosome
Phagolysosome
A sudden increase in disease cases above expected levels
Epidemic
Difference between mechanical and biological vectors
Mechanical = no replication; Biological = replication occurs
Proteins that enhance pathogen destruction and can form MAC
Complement system
Cells that kill virus-infected or tumor cells
Natural killer cells
Process where leukocytes leave bloodstream to enter tissues
Diapedesis
Explain the difference between incidence and prevalence
Incidence = new cases; Prevalence = total cases
A contaminated doorknob spreading disease is what type of transmission?
Indirect contact (fomite transmission)
Name TWO outcomes of complement activation
Opsonization, inflammation, cytolysis
Cells that engulf pathogens and present antigens to adaptive immunity
Macrophages / Dendritic cells
Explain ONE benefit and ONE risk of fever
Benefit: inhibits pathogen growth / boosts immune response
Risk: tissue damage if excessive