6) Infectious diseases Flashcards
factors influencing acquisition of infectious diseases
- immune status
- incidence in pop
- pathogenicity
- dosage
- portal of entry
- host age, history of exposure
most active constituents against organisms free in blood or tissues
complement and Ig
most active against organisms inside cells
cell mediated response
body’s main defense against bacteria
lysozyme
phagocytosis
lysozyme is good at destroying…
GP cell walls
allow bacteria to survive/evade phagocytosis
- capsule
- cell wall
- endotoxins
fungus may enter resp tract as…
spores
main defense against viruses
interferon
T-cell system
3 functions of interferon
- signals uninfected cells to destroy viral rna
- signals infected cells to undergo apoptosis
- activates NK cells
viruses that persist in dormant phase can cause…
- serious disease
- tumors
—— viruses have especially high mutation rate
RNA
intermediates between viruses and bacteria
- rickettsiae
- mycoplasma
obligate intracellular organisms with cell walls
closer to virus
rickettsiae
no cell wall but capable of extracellular replication
closer to bacteria
mycoplasma
immune defense against parasites
- IgE
- eos
- complement
- NK cells (Ab-dependent, cell-mediated cytotoxicity)
