Infection and Disease Flashcards
➢the invasion or colonization of the body by pathogenic microorganisms.
Infection
➢the presence of a particular type of microorganism in a part of the body where it is not normally found and may lead to disease
Infection
➢ occurs when an infection results in any change from a state of health.
Disease
➢an abnormal state in which part or all of the body is incapable of performing its normal functions.
Disease
➢the ability to cause disease by overcoming host defenses.
Pathogenicity
➢ the degree of pathogenicity
Virulence
To cause disease, most pathogens must:
✓ gain access to the host
✓adhere to host tissues
✓penetrate or evade host defenses
✓ damage the host tissues
Portals of Entry for Pathogens
✓mucous membranes
✓skin
✓direct deposition beneath the skin or membranes (the parenteral route)
Mucous Membranes: Microbes are inhaled into the nose or mouth in drops of moisture and dust particles.
Respiratory tract
Mucous Membranes: Microorganisms can gain access to the ________ in food and water and via contaminated fingers.
Gastrointestinal tract
Mucous Membranes: portal of entry for pathogens that are contracted sexually.
Genitourinary tract
Mucous Membranes: delicate mucous membrane that lines the eyelids and covers the white of the eyeballs.
Conjunctiva
➢ portal of entry for pathogens by deposition directly into tissues beneath the skin and mucous membranes when these barriers are penetrated or injured.
Parenteral Route
➢attachment of a microbe or phagocyte to another’s plasma membrane or other surfaces
➢necessary step in pathogenicity
Adherence
➢A carbohydrate-specific binding protein that projects from prokaryotic cells
➢binds specifically to complementary surface receptors on the cells of certain host tissues
➢used for adherence
➢may be located on a microbe’s glycocalyx or on other microbial surface structures, such as pili, fimbriae, and flagella
Adhesin
