immune system- section 2, innate immunity

Question 1

what are the two systems?

Answer 1

Innate and adaptive immune system

Question 2

innate immune system

Answer 2

relatively rapid but non specific

Question 3

adaptive immune system

Answer 3

slower in its development following infection, but highly specific and effective attacking a wide variety of pathogens

Question 4

what system is the skin apart of? how does it add to this system?

Answer 4

• innate immune system
• skin covered with dead layer of epithelium that is too dry for bacteria to grow, cells are continually shed off and carry bacteria and pathogens with them
• sweat and other skin secretions lower pH, contain toxic lipids, contain antimicrobial peptides, physically wash microbes away

Question 5

what system is mucus membrane apart of and how does it help

Answer 5

innate immune system
- saliva in mouth is rich in lysozyme- enzyme that destroys bacteria by digesting their cell walls
- acidic environment of the stomach- fatal to many pathogens
- mucus layer of gastrointestinal tract, respiratory, reproductive tracts, eyes, ears, nose traps microbes and debris

Question 6

what happens when a microorganism bypasses the body protective layers?

Answer 6

• attacked by the cells of the innate immune system

Question 7

what are phagocytes?

Answer 7

cells that take microorganism inside themselves in vesicles called phagosomes- fuses with a lysosome and its digestive enzyme

Question 8

phagocytes consist of

Answer 8

• macrophages (either roaming freely thru connective tissues or fixed to fibres w/in specific tissues like lymph nodes
• dendritic cells (found in mucus membrane, activate immune response)
• neutrophil
  (recruited from bloodstream to infected tissues, first responders to cite of infection)

Question 9

Natural killer cells have ability to induce

Answer 9

apoptosis (programmed cell death) in cells infected with intracellular pathogens (bacteria, virus)
- dying cells shrivel up, trapping pathogens inside, phagocytoses by macrophages

Question 10

inflammation

Answer 10

• primary response to injury, can be triggered by infections and tissue damage
• acute and chronic inflammation

Question 11

what are 4 phases of inflammatory response

Answer 11

• tissue injury
• vasodilation
  -increased vascular permeability
• recruitment of phagocytes

Question 12

explain tissue injury phase

Answer 12

injured cells stimulate the release of MAST CELL granules and the potent inflammatory mediators

Question 13

explain vasodilation

Answer 13

• inflammatory mediators such as histamine are vasodilators that increase diameters of local capillaries
• causes increased blood flow and is responsible for heat, redness of inflamed tissue, allows greater access of immune components of blood to sit of inflammation

Question 14

increased vascular permeability

Answer 14

• inflammatory mediators increase permeability causing leakage of fluid into interstitial space, resulting in swelling or EDEMA

Question 15

recruitment of phagocytes

Answer 15

• inflammatory mediators attract NEUTROPHILs from blood to site of infection
• more macrophages recruits to clean up debris remaining at site
• as they phagocytose the pathogens and subsequently die, their accumulated cellular remains are visible as PUS

Question 16

soluble mediators

Answer 16

molecules secreted in the blood.
- complement proteins (label pathogens for phagocytosis)
- transferrin (reduces availability of iron in the blood which can reduce growth of microbes)