Lecture 10 Flashcards Preview

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Flashcards in Lecture 10 Deck (45):
1

Innate immunity refers to..

defences that are present at birth

2

Innate immunity are non specific defences acting against...

most microbes in the same way

3

Innate immunity has no memory component so it cannot

recall previous contact w/ foreign microbe

4

Innate immune system is always present as it..

-responds rapidly to an infection
-active before an infection

5

Innate immune system includes..

-physical barriers
-chemical barriers
-cellular defences
-inflammation
-fever
-molecular defences

6

Types of leukocytes

-granulocytes
-agranulocytes

7

Granulocytes

large granules in their cytoplasm and are under light microscope

8

3 sub groups of granulocytes

-basophils
-eosinophils
-neutrophils

9

Basophils

weak phagocytes, they secrete chemo-attractants and release histamine which causes allergies and inflammation

10

Eosinophils

destroy large pathogens which as pathogenic worms, produce extracellular digestive enzymes to attack parasite

11

Neutrophils

strong phagocytes, leave the blood and enter infected tissue, destroy foreign microbes and particles by phagocytosis

12

Agranulocytes

have granules in their cytoplasm which are visible under high microscope

13

3 types of agranulocytes

-monocytes
-lymphocytes
-dendritic cells

14

Monocytes

initially not phagocytic, are immature. they leave the blood, enter into tissue and become macrophages

15

Macrophages

mature monocytes and strong phagocytes, often found in organs and filter out invading pathogens as blood passes through

16

Dendritic cells

present foreign material to cells of the adaptive immune system, antigen presentation

17

3 types of lymphocytes

-natural killer cells (NK cells)
-T lymphocytes
-B lymphocytes

18

Natural killer cells

responsible for killing infected body cells and tutor cells, they attack any body cell that displays unusual proteins in the plasma membrane

19

B and T lymphocytes

part of adaptive immunity

20

Phagocytes

during infection monocytes and granulocytes migrate to the infected area

21

4 main phases of phagocytosis

-chemotaxis
-adherence
-ingestion
-digestion

22

Chemotaxis

phagocytes are attracted to foreign particles, damaged cells etc

23

Adherence

phagocyte attaches to a foreign particle

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Ingestion

pseudopods extend and engulf the particle, the particle is trapped in the phagosome

25

Digestion

digestive enzymes enter the phagosome, takes 10-30 min to kill bacterium

26

Inflammation signs and symptoms

-pain
-redness
-heat
-swelling
-loss of function

27

Inflammation functions to..

destroy an injurious agent and prevent the spreading of an injurious agent, it repairs and replaces damaged tissue

28

Stages of inflammation

-tissue damage
-vasodilation
-phagocytosis
-tissue repair

29

Vasodilation

blood vessels dilate more blood reaches affected area, this allows white blood cells to access the area, brings nutrients for fast healing

30

Vasodilation causes..

reddening, swelling (edema), increased temp and pain (due to tissue damage)

31

Vasodilation allows..

fibrinogen to clot formation, this segregates the affected area and prevents spread of infection

32

Phagocytosis

phagocytes destroy invading microbes

33

Fever

increase in body temp, controlled by hypothalamus

34

Fever is triggered by..

toxins, LPS, and chemical produced by the immune system (reset the bodies thermostat)

35

Fever results in..

-muscle contraction
-increased temp (faster metabolism, promotes healing)
-faster phagocytosis
-slows growth of heat limited microbes
-up to a certain temp, fever is defence against disease

36

Complement system

composed of 30 proteins that circulate in the blood, work together as a cascade (the action of one protein triggers the action of the next)

37

Complement can be triggered by..

surface molecules of invading microbes

38

Result of complement cascade

-opsonization
-enhance inflammation
-cytolysis

39

Opsonization

C proteins attach to microbes and act as a flag to attract phagocyte, this increases phagocytosis by 1000x.

40

Enhance inflammation

increases blood vessel permeability, attracts phagocytes to the infection site

41

Cytolysis

formation of the membrane attack complex (MAC), pokes holes in the bacterial cell membrane

42

Interferon (IFN)

produced upon infection with a virus, interferes with viral replication, can be toxic to organs, released by infected cells to warn neighbouring cells. doesn't help cells already infected w/ virus

43

IFN allows neighbouring cells..

time to produce anti-viral proteins

44

IFN is effective only..

for short periods of time

45

Side effects of IFN include

-nausea
-fatigue
-headache
-vomiting
-fever