pathophys podcast 10 ch

Host

organism that can support another organism’s growth (pathogen)

Infection

presence and multiplication of microorganisms within a host causing injury

Infectious disease

host tissue damage resulting from interaction with a pathogen

Colonization

presence and multiplication of microorganisms without harm

Microflora

commensal organisms normally inhabiting body surfaces

Virulence

pathogen’s capacity to cause disease

Pathogen

microorganism that typically produces disease once infecting host

Saprophyte

organism that feeds on dead or decaying organic matter and rarely causes disease

Commensalism

relationship where microorganism benefits and host is unaffected

Mutualism

interaction in which both host and microorganism benefit

Parasitism

relationship where microorganism benefits at expense of host

Types of pathogens

prions (protein-only), viruses (obligate intracellular), bacteria, fungi, protozoa, helminths

Stages of pathogenesis

exposure → adhesion/colonization → invasion → infection → damage/transmission

Portals of entry

skin breaches, mucous membranes, inhalation, ingestion, vectors

Transmission routes

direct contact, indirect contact (fomites), droplet, airborne, vector-borne, vehicle-borne

Incubation period

time from pathogen entry to onset of symptoms

Prodromal stage

early, nonspecific symptoms before full disease

Acute stage

period of maximum disease intensity and pathogen proliferation

Convalescent stage

pathogen load decreases, symptoms resolve, repair begins

Resolution stage

infection clears, host returns to normal or residual damage remains

Local vs systemic infection

confined to one anatomical area vs spread through bloodstream or lymph

Primary vs secondary infection

primary = initial invasion

secondary = follows primary or immunosuppression

Opportunistic pathogen

organism causing disease when host defenses are impaired

Virulence factors

mechanisms like toxins, adhesion molecules, immune evasion strategies

Koch’s postulates

criteria historically used to link specific microorganisms to specific diseases [oai_citation

Host–pathogen interaction triad

involves pathogen, host (susceptibility), environment in disease development [oai_citation