immune system (innate)

Question 1

when is innate defence present?

Answer 1

at birth. always at work.

it is non-specific

Question 2

what does innate defence include?

Answer 2

physical barriers
cellular defense
chemical defense
inflammation

Question 3

what is the first line of defense?

Answer 3

physical barriers

Question 4

what are the 2nd line of defense?

Answer 4

cellular and chemical defense

Question 5

what is a physical barrier?

Answer 5

skin and mucous membranes

epithelial membranes- form physical barriers and produce secretions

Question 6

antimicrobial secretions include?

Answer 6

acid, enzymes, mucous, defensins, dermcidin

Question 7

acid..?

Answer 7

skin vaginal and stomach secretions have low pH inhibits bacterial growth

Question 8

enzymes?

Answer 8

lysozyme in tears and saliva LYSES bacteria. proteases digest microorganisms

Question 9

mucus?

Answer 9

sticky secretion in respiratory/ digestive passages; trapsmicroorganisms

Question 10

defensins?

Answer 10

antimicrobrial peptides secreted by mucous membranes; inhibit bacterial and fungal growth

Question 11

dermcidin?

Answer 11

secretion in sweat that is toxic to bacteria

Question 12

what is cellular defense?

Answer 12

phagocytes. example= macrophages derived from monocytes; may be free or fixed. also neutrophils.

Question 13

cellular defense: intracellular killing

Answer 13

engulfs bacteria by phagocytosis, lysosomal enzymes digest the pathogen! food. yum.

Question 14

what are TLRs

Answer 14

toll like receptors! phagocytes have these special buddies that recognize the pathogen associated molecules! cool little detectives.

Question 15

cellular defense: extracellular killing

Answer 15

neutrophils degranulate, so they release granules that contain toxins.
can be: proteases, defensins, free radicals
proteases- protein digesting enzymes
defensins- pierce holes in cells
free radicals- oxidizing chemicals

Question 16

what is NET….

Answer 16

last resort…. suicide of the neutrophils! they release their genetic material and net bacteria, and they DIE… :(
stands for neutrophil extracellular trap

Question 17

what are natural killer cells….. NK cells..

Answer 17

IMMUNE surveillance….. special granular lymphocytes that recognize and attack abnormal cells
they release cytolytic chemicals… these chemicals destroy cells that are virus infected or cancerous

Question 18

steps of the NK cells on attack..

Answer 18

1. recognize abnormal cell
2. AIM. align golgi apparatus
3. FIRE. perforin makes holes and granzymes enter cell
4. APOPTOSIS- programmed cell death

Question 19

normal flora and cellular defense?

Answer 19

inhabit epithelial surface, increase competition and stimulate defense mechanisms to protect against pathogens

Question 20

chemical defense?

Answer 20

chemicals circulating in blood or released by injured/infected cells and leukocytes

Question 21

pyrogen

Answer 21

released by phagocytes exposed to pathogens

FEVER…. alters temp set point in hypothalamus. increased temp accelerates repair and enhances activity of immune cells

Question 22

interferons

Answer 22

secreted by virus infected cells

“interfere” with replication in nearby cells and attract NK cells

Question 23

complement

Answer 23

group of plasma proteins, activated by microbes, activation cascade.
made in the liver, circulate in blood.

Question 24

3 main pathways of complement

Answer 24

classical
alternative
lectin

Question 25

classical pathway?

Answer 25

contacts an antigen-antibody complex

Question 26

alternative pathway?

Answer 26

contacts surface of a microbe

Question 27

lectin pathway?

Answer 27

contacts plasma protein lectin bound to sugar mannose on surface of pathogen

Question 28

how does complement activation enhance phagocytosis?

Answer 28

makes the pathogens very yummy!!

Question 29

how does complement activation enhance inflammation

Answer 29

causing mast cells to release histamine!!

Question 30

how does complement activation enhance chemotaxiss

Answer 30

creates chemical trail that attracts leukocytes!!

Question 31

how does complement activation enhance cell lysis

Answer 31

forms a membrane attack complex which creates holes in cell membranes!!

Question 32

what is the formation of the MAC complex

Answer 32

cascade of activation events results in an assembly of complement proteins that insert into the bacterial cell wall, form pores and holes and cause LYSIS of cell as water rushes in

Question 33

inflammation is..?

Answer 33

non-specific response triggered by tissue injury, chemical irritation, pathogens

Question 34

4 cardinal signs

Answer 34

swelling
redness
heat
pain

Question 35

during inflammation basophils and mast cells…

Answer 35

release inflammatory mediators (histamine, kinins, prostaglandins; complement proteins activated)

Question 36

3 main effects from the infection/injury

Answer 36

vasodilation, increased capillary permeability and attracts wbcs (chemotaxis)

Question 37

vasodilation causes

Answer 37

hyperemia (increased blood flow)
causes redness and heat
causes more nutrient supply, more repair

Question 38

increased capillary permeability causes

Answer 38

fluid leakage and leukocytes escape from blood into c.t
“diapedesis”
swelling and pain

Question 39

chemotaxis causes

Answer 39

fight pathogens, dispose of damaged cells

Question 40

what is margination

Answer 40

leukocytes stick and roll along blood vessel wall