6.3 Innate Immunity (Second Line of Defense)

Question 1

Innate Immunity:

Answer 1

Non specific (there is no differentiation between particular pathogens)
Non-adaptive (the response is the same upon every infection)

Question 2

Components of innate immune system

Answer 2

Inflammation (increase capillary permeability at infected sites to recruit leukocytes)
Phagocytosis (the engulfment and destruction of pathogens by phagocytic cells)
Antimicrobial Proteins (regulate immune activity via complement system)
Fever (increase body temperature to suppress microbial growth and propagation)

Question 3

Inflammation

Answer 3

Upon tissue damage, mast cells (local) and basophils (circulating) release histamine
Causes local vasodilation (redness) and increases capillary permeability (swelling)
Improves the recruitment of leukocytes to the infected region

Question 4

Process of Inflammation

Answer 4

Damages cells release chemotactic factors
Mast cells / Basophils release histamine
Localised vasodilation increases capillary permeability

Question 5

Phagocytosis Explained

Answer 5

Monocytes (macrophages and dendritic cells) can ingest pathogens non-specifically via phagocytosis
- Pseudopia surrounds the pathogen and fuses to internalise the pathogen inside a vesicle
- The besicle is then transported to the lysosome

Question 6

Complement System

Answer 6

consists of antimicrobial protein that function to augment and enhance innate immune responses

Question 7

Complement Proteins may (Complement System

Answer 7

Chemotaxis (attack phagocytic cells to sites of infection)
Opsonization (enhance phagocytosis by marketing antigens for an immune response
Membrane attack (ruptures bacterial cell walls by forming a porous complex)

Question 8

Fever

Answer 8

an abnormal;y high body temperature associated with infection
- Reduces the growth rate of pathogens and activates heat-shocj proteins
- Beyond a tolerable limit, fever can cause damage to the bodys own enzymes

Question 9

Process of Fever

Answer 9

Pathogens (activate)
Leukocytes (release)
Cytokines (stimulate)
Hypothalmus (produce)
Prostaglandins (trigger)
Fever

Question 10

Natural Killer Cells

Answer 10

non-specific target compromised host cells for apoptosis
Used to combat both tumors and infected by viruses
Activated by interferibs or macrophage-derived cytokines
Target host cells that display an altered state
Are lymphocytes but function as part of the innate immune system