Immunology 1

Question 1

lymphatic organs

Answer 1

thymus
spleen
tonsils
lymph nodes

Question 2

innate immune cell

Answer 2

myeloid progenitor

Question 3

adaptive immune cell

Answer 3

lymphoid progenitor

Question 4

macrophages

Answer 4

antigen presentation when they ingest bacteria and tissue debris

Question 5

dendritic cells

Answer 5

phagocyte and activate adaptive immune cells

Question 6

T cells

Answer 6

70 - 80% of blood lymphocytes

Question 7

lymphoid organs

Answer 7

specialised organs and collections of tissue where lymphocytes interact with non lymphoid organs

Question 8

primary lymphoid organs a.k.a. generative organs

Answer 8

hematopoietic stem cells differentiate into mature immune cells

bone marrow + thymus

Question 9

secondary lymphoid organs

Answer 9

1. lymph node
2. spleen: clearance and mounting against blood borne antigens
3. MALT: mucosal associated lymphoid tissue
   > digestive, respiratory, uro genital tract

Question 10

lymph nodes

Answer 10

lymphatic capillaries are blind ended and it is here that there is a passive movement of fluid into lymphatic vessels

at the lymph node the lymph encounters immune cells at the germinal centres

cortex + para cortex = macrophages + dendrites which will present antigen to T and B cells

B cells: localised in the cortex within follicles or germinal centres

T cells: distributed more diffusely in paracortical areas or T cell zones

Question 11

germinal centres

Answer 11

sites of lymphocyte proliferation

Question 12

spleen

Answer 12

filters blood with major role for removing senescent RBCs

lymphocytes make up the white pulp

Question 13

MALT (loads of B cells)

Answer 13

can range from loose barely organised diffuse collections of lymphoid cell

also well organised structures such as peyers patch found in intestinal lining

MALT has high number of B cells more than spleen, lymph node + bone marrow combined.

Question 14

peyers patch

Answer 14

consisted of germinal centre with loosely organised B cells along with lymph vessel.

M cells actively transport in both directions allowing the B cells of the peyers patch to sample the gut environment.

Question 15

memory cell migration site

Answer 15

lymph nodes
circulate in the blood
mucosal tissue

Question 16

innate immunity

Answer 16

recognition of common microbial patterns
signalling molecules are released i.e. cytokines
inflammation can also occur and recruitment of effector cells

Question 17

epithelial barrier

Answer 17

physical barrier by keratinocytes

mucus/cilia to remove particles

acid pH of stomach

antimicrobial peptides; 7 angstrom proteins which secrete peptides that puncture bacterial cell wall causing it to lose its osmotic pressure and rupture

Question 18

PRRs

Answer 18

pathogen recognition receptors

recognise things such as PAMPs = pathogen associated molecular patterns

PAMPs target microorganism components that are absolutely essential for microorganism survival/pathogenicity and are not prone to mutation

e.g. DNA, cell walls

Question 19

TLRs

Answer 19

are a type of PRR

Question 20

TLR 4

Answer 20

recognises LPS on the outer coat of gram negative bacteria and binds to it

Question 21

TLR 2

Answer 21

recognises gram + bacteria

Question 22

TLR 5

Answer 22

recognises flagella

Question 23

TLR 9

Answer 23

recognises bacterial DNA (methyl group)

Question 24

TLR 3

Answer 24

recognises double stranded RNA of viruses

Question 25

complement cascade

Answer 25

collection of circulating and membrane associated proteins and their activation will trigger the cascade

many complement proteins are proteolytic enzymes

can be activated by both innate and adaptive immune system

finishes at C9 which lysis the microbe

Question 26

complement cascade pathways

Answer 26

alternative pathway: microbe structure triggers (innate initiation)

classical pathway: antibody binding triggers

lectin pathway: mannose binding lectin

Question 27

complement cascade method of killing pathogen

Answer 27

inducing inflammation which recruits phagocytes

coating the microbe which recruits and encourages phagocytosis

forming membrane attack complex (lysing the cell)

Question 28

complement cascade components

Answer 28

C3a: drives inflammatory process and stimulates other innate immune cells

C3b: deposited onto microbe causing microbes to undergo opsonisation (coagulate together)

C5a: potent inducers of inflammation

C9: membrane attack complex, 9 angstrom pore that impales the surface of the pathogen

Question 29

phagocytic process

Answer 29

pseudopodia = invagination which encapsulates the bacteria

bacteria is contained in phagosome

phagosome fuses with lysosome

Question 30

NK cells granulocytes

Answer 30

granzyme + perforin which is pumped in virally infected and cancer cells

Question 31

neutrophils

Answer 31

50% of all WBC and only live for 24 hours

envelop bacteria through phagocytosis, digest + kill

cell receptors:
CR4
TLR 4 (LPS)
Mannose receptors (Lectin pathway)

they also detect cytokines and chemokines released by endothelium, mast cells + macrophages causing their chemotaxis

contain antimicrobial proteins

Question 32

macrophages

Answer 32

phagocytosis
bactericidal activity
inflammatory response (produce many cytokine)
APC

last for months

Question 33

fixed macrophages

Answer 33

dust/alveolar type

histiocytes = connective tissue

kupffer cells = liver

microglia = CNS

osteoclasts = bone

sinusoidal lining cells = spleen

Question 34

chemokines

Answer 34

are a type of cytokine which function as chemo attractants and regulate cell motility e.g. IL - 8

Question 35

sepsis

Answer 35

large amount of cytokines released would result in systemic edema, decreased blood volume, hypoproteinaemia, neutropenia

decrease in blood volume = collapse of blood vessels