[DISCUSSION] MODULE 2 UNIT 1 Flashcards
(268 cards)
Innate immunity
NATURAL IMMUNITY
Ability of the individual to resist infection
NATURAL IMMUNITY
Normally present body functions
Ability of the individual to resist infection
NATURAL IMMUNITY is Considered:
• Non adaptive
• Nonspecific
Same for all pathogens or foreign substances
NATURAL IMMUNITY
• No prior exposure is required
NATURAL IMMUNITY
• No prior exposure is required
• Response does not change = same magnitude every time
NATURAL IMMUNITY CHARACTERISTICS:
- Components are preformed
- Standardized
- Without memory
- Nonspecific
NATURAL DEFENSE SYSTEM
• TWO PARTS:
• External defense system
• Internal defense system
EXTERNAL DEFENSE SYSTEM
• Composed of:
- Anatomic barriers
- Physiologic barriers
• Prevent most infectious agents from entering the body
Anatomic barriers
Anatomic barriers Examples:
• Intact skin
• Mucous membranes
Physiologic barriers
• Temperature
• Low pH
• Physiologic functions → coughing, sneezing, vomiting, diarrhea,
shedding of cells
• Oxygen tension
• Age
• Hormonal balance
• Chemical mediators → lysozyme, interferon, complement, toll-like
receptors, collectins
Physiologic functions
coughing, sneezing, vomiting, diarrhea,
shedding of cells
Chemical mediators
lysozyme, interferon, complement, toll-like
receptors, collectins
• Cleaves bacterial cell wall
• Lysozyme
• Induces antiviral state in uninfected cells
• Interferon
• Lyses microorganisms or facilitates phagocytosis
• Complement
• Recognize microbial molecules
• Toll-like receptors
• Signal cell to secrete immunostimulatory cytokines
• Toll-like receptors
→ disrupt cell wall of pathogen
• Collectins
• Second line of defense
INTERNAL DEFENSE SYSTEM
• Cells and soluble factors
INTERNAL DEFENSE SYSTEM
• Designed to recognize molecules that are unique to
infectious organisms
INTERNAL DEFENSE SYSTEM