immunology

Question 1

megakaryocytes become

Answer 1

platelets

Question 2

reticulocytes become

Answer 2

RBC

Question 3

myeloblasts become

Answer 3

neutrophils
monocytes -> macrophages
eosinophils
basophils

Question 4

myeloid stem cells become

Answer 4

megakaryocytes
reticulocytes
myeloblasts
mast cells

Question 5

pluripotent haematopoietic stem cells become

Answer 5

myeloid stem cells
lymphoid stem cells
dendritic cells

Question 6

lymphoid cells become

Answer 6

b cells
t cells
natural killer cells

Question 7

b cells become

Answer 7

plasma cells

memory b cells

Question 8

t cells become… which then become…

Answer 8

CD4 cells -> T helper cells (activate CD8 cells to become cytotoxic T cells)
CD8 cells

Question 9

briefly describe innate immune system

Answer 9

cells already at location of infections
respond immediately
generalised response

Question 10

briefly describe specific immune system

Answer 10

takes longer than innate esp if first infection
specialised
away from location of infection

Question 11

what do both mast cells and basophils contain

Answer 11

cytoplasmic granules containing cytokines released in response to pathogen

Question 12

function of macrophage

Answer 12

first line of defence

have toll-like receptors used to recognise pathogen associated molecular patterns (PAMPs)

Question 13

define PAMPs

Answer 13

pathogen associated molecular patterns that are recognised by toll like receptors on macrophages

Question 14

function of neutrophil

Answer 14

general attack cell in innate immune system
circulate in blood and migrate to areas of inflam in response to macrophage signals
Fastest responding WBC
Antigen presenting
Release lysosomes, defensins and strong oxidants that directly destroy bacteria

Question 15

function of eosinophil

Answer 15

parasitic infection
stay in tissues until activated
granules contain pro-inflam cytokines & toxic chems eg. ‘major basic protein’ - released in degranulation/exocytosis process

Question 16

function of b cell and its differentials

Answer 16

antibodies (immunoglobulins) on outside of cell
they match to antigens displayed on pathogen
once activated, they differentiate into plasma cells (produced lots of that specific antibody) and memory B cells (await future infection)

Question 17

function of t cell and its differentials (big boi)

Answer 17

have specific t cell receptors on surface to recognise antigens
differentiate into CD4 and CD8 cells
CD4: respond to HLA class II, become T helper cells which activate CD8 to differentiate into cytotoxic T cells (cell lysis and FAS pathway)
CD8: respond to HLA class I

Question 18

function of natural killer cells

Answer 18

activated by cytokines from macrophages and interferons
don’t require receptor antigen recognition to be activated
induce cell death (apoptosis)
release interferon gamma to activate macrophages (cycle of posi feedback)

Question 19

function of dendritic cells

Answer 19

present antigens of pathogens on cell membrane
have HLA class I & II (for both CD4 & CD8)
act as postman - carry antigens through lymphatic tissue to T cells

Question 20

physical barrier examples

Answer 20

skin - blocks bacteria but break in this can lead to infection
mucosa of: resp system, GI tract, urinary tract

Question 21

chemical barrier examples

Answer 21

HCl of stomach
lactic acid of vagina
lysozyme in sweat and tears

Question 22

cytokine release lead to inflammation which causes…

Answer 22

monocytes and neutrophils to be activated
vasodilation
increased vascular permeability
mast cell degranulation
clotting system activated
kinin system activated

Question 23

what is the acute phase response

Answer 23

systemic response using interleukins

Question 24

function of interleukin 1

Answer 24

sent to brain to produce fever (pathogens have poor tolerance), poor appetite & lethargy to conserve energy for fighting infection

Question 25

function of interleukin 2 & 12

Answer 25

activates natural killer cells

Question 26

function of interleukin 6

Answer 26

sent to liver to activate/produce acute phase proteins (opsonins)

Question 27

function of opsonins

Answer 27

extracellular acute phase protein attach to pathogens, making them more recognisable to macrophages/inducing phagocytosis eg. c-reactive protein, measured clinically as marker of inflam/infection

Question 28

function of interleukin 8

Answer 28

recruits and activates neutrophils

Question 29

function of tumour necrosis factor

Answer 29

``` used in acute phase response multifunctional cytokine important roles in diverse cellular events such as cell survival, proliferation, differentiation, and death fights infection (does all of the interleukin roles itself) ```

Question 30

describe phagocytosis

Answer 30

macrophages recognise PAMPs using toll-like receptors engulf pathogen into a phagosome lysosome in cell fuses with phagosome lysosome releases digestive enzymes and breaks down pathogen releases cytokines to trigger inflammation

Question 31

lectin pathway trigger

Answer 31

directly by pathogens

Question 32

alternative pathway trigger

Answer 32

directly by pathogens

Question 33

classical pathway trigger

Answer 33

antibody-antigen complex

Question 34

describe complement system

Answer 34

proteins activate each other in cascade enhances (complements) the ability of antibodies and phagocytic cells to clear microbes and damaged cells from an organism, promote inflammation, and attack the pathogen's cell membrane

Question 35

describe specific immune response

Answer 35

1. dendritic cell displays antigen on HLA class II molecule to CD4 cells in lymphatic tissue which proliferate into T helper cells 2. THC present antigen on HLA class I molecule (recognised by HLA class I molecule) and release cytokines 3. cytokines encourage proliferation/differentiation of CD8 into cytotoxic T cells and B cells to become plasma and memory cells

Question 36

what are cytotoxic cells responsible for

Answer 36

killing virally infected cells via spraying cytokines = cell lysis OR FAS pathway = self destruction

Question 37

what are cytotoxic cells responsible for

Answer 37

``` killing virally infected cells T cell receptor bind with HLA class I holding antigen on infected cell either spraying cytokines = cell lysis OR FAS pathway = self destruction ```