L18: Immunology I

Question 1

3 functions of the immune system

Answer 1

1) Respond to infection by micro-organisms
2) Repair damaged tissues
3) Retard cancer development

Question 2

How does the immune system represent a number of surveillance mechanisms?

Answer 2

Capable of recognising self vs non-self
- Secrete protective substances into bodily fluids
- Launch cellular response

Question 3

2 parts of the immune system

Answer 3

1) Innate Immunity

2) Adaptive Immunity

Question 4

Features of innate immunity

Answer 4

1) Non-specific
2) Rapid
3) Response to infections
4) Can be humoural/cell-mediated

Question 5

Define humoural

Answer 5

Secreted things

Question 6

Define cell mediated

Answer 6

Cells that target damaged site

Question 7

Features of adaptive immunity

Answer 7

1) Specific
2) Slow to develop
3) Response to infections
4) Humoural/cell mediated

Question 8

Are cells of the innate response highly or slightly phagocytic?

Answer 8

Highly phagocytic

Question 9

What proteins does the cells of the innate reponse contain that destroy engulfed bacteria, cellular debris or foreign particulate matter

Answer 9

Lysosomal & microbiocidal proteins

Question 10

Names for macrophages in liver

Answer 10

Kupffer cells

Question 11

Names for macrophages in bone

Answer 11

Osteoclasts

Question 12

Names for macrophages in kidney

Answer 12

Mesangial cells

Question 13

Names for macrophages in brain

Answer 13

Microglia

Question 14

Describe neutrophil action

Answer 14

They only survive for only a few days, constantly replaced

Question 15

Two forms of ‘killer’ cells

Answer 15

Natural killer cells
Eosinophils

Question 16

Describe natural killer cells

Answer 16

Attach to virally infected cells/tumour cells by causing pores to form in the target cell membrane inducing a apoptotic death

Question 17

Describe eosinophils as a ‘killer’ cell

Answer 17

Contain granules with cytotoxic proteins that attach to, and kill, parasites

Question 18

Are adaptive immune cells or innate immune cells slower to react?

Answer 18

Adaptive Immune Cells

Question 19

Define antigens

Answer 19

A toxin or foreign substance which induces an immune response in the body

Induce a T cell / B cell response
Can be a protein, lipid, carbohydrate or nucleic acid

Question 20

Define antibodies

Answer 20

Glycoprotein that interacts with a specific antigen
- Can neutralise the antigen to induce phagocytosis by macrophages

Question 21

Can adaptive response be both cellular & humoural?

Answer 21

Yes

Question 22

Why are lymphocytes adaptive immune cells?

Answer 22

Can differentiate into memory cells, which can respond faster & more efficiently the next time the same pathogen invades

Question 23

2 functional classes of lymphocytes

Answer 23

1) B cell
2) T cell

Question 24

Where does lymphocytes circulate & become activated?

Answer 24

Circulate in blood & lymph and become activated in secondary lymphoid organs

Question 25

Where does B cells arise & mature in?

Answer 25

Arise in bone marrow Mature in bone marrow

Question 26

Where does T cells arise & mature in?

Answer 26

Arise in bone marrow Mature in thymus

Question 27

Where are B cells & T cells activated in?

Answer 27

Secondary lymphoid organs

Question 28

Function of B cells

Answer 28

Secrete antibodies specific to target antigen ## Footnote Activated by antigen & helped along by Helper T cells, secrete antibody when activated

Question 29

Function of T cells

Answer 29

Induce a cell-mediated adaptive immune response ## Footnote Direct & recruit other cells of immune system as well as attacking diseased cells directly

Question 30

What is long term immunity maintained by in B cells?

Answer 30

Memory B cells

Question 31

What is long term immunity maintained by in T cells?

Answer 31

Memory T cells

Question 32

What receptors are responsible for recognition of antigen?

Answer 32

Specific T cell receptors (TCR)

Question 33

4 functional subsets of T cells

Answer 33

1) Helper T cells 2) Cytotoxic T cells 3) Regulatory T cells 4) Memory T cells

Question 34

Function of Helper T cells

Answer 34

Activate B cells

Question 35

Function of Cytotoxic T cells

Answer 35

Kill infected cells (antigen)

Question 36

Function of Regulatory T cells

Answer 36

Help module responses

Question 37

What can antibodies do when it is secreted?

Answer 37

Neutralise the pathogen Facilitate uptake of phagocytes (opsonization)

Question 38

Define opsonization

Answer 38

An immune process which uses opsonins to tag foreign pathogens for elimination by phagocytes

Question 39

2 functional subsets of B cells

Answer 39

1) Plasma cells 2) Memory cells

Question 40

Define VDJ recombination

Answer 40

Somatic recombination occuring in developing lymphocytes during early stages of T & B cell maturation

Question 41

Role of FC region on antibody

Answer 41

Signals macrophages when binded to antibodies

Question 42

When does lymphocyte activation occur?

Answer 42

When lymphocytes (B cells or T cells) are triggered through antigen-specific receptors on their cell surface

Question 43

# B cells Lymphocyte activation in B cells

Answer 43

1. Surface immunoglobin binding to B cells 2. Clonal expansion occurs creating plasma cells & memory B cells

Question 44

# T cells Lymphocyte activation in T cells

Answer 44

1. Antigen presentation via antigen presenting cell 2. Clonal expansion occurs 3. Producing T helper cell, cytotoxic cells & memory T cells

Question 45

2 tissues of the immune system

Answer 45

Primary Lymphoid Tissues Secondary Lymphoid Tissues

Question 46

Primary Lymphoid Tissues

Answer 46

Immature lymphocytes acquire the capacity for antigen recognition

Question 47

Secondary Lymphoid Tissues

Answer 47

Site of lymphocyte activation

Question 48

Describe the thymus

Answer 48

Encapsulated organ with 2 lobes located in the lower - Site of T cell maturation ## Footnote 1) Aquisition of T cell immunocompetence 2) Development of immunological self tolerance

Question 49

What are lymph nodes?

Answer 49

Small organs found in groups/chains in sites where lymphatic vessels drain to an anatomic region

Question 50

2 functions of the lymph nodes

Answer 50

1) Phagocytic cells act as non-sepcific filters of particulate matter 2) Location where lymphocytes interact with new antigens & APCS, facilitate activation of an immune response

Question 51

Structure of lymph nodes

Answer 51

Surrounded by fibrocollagenous capsule, surface is penetrated by a number of afferent vessels

Question 52

Function of follicles in lymph nodes

Answer 52

Regions of B cell activation

Question 53

What does germinal center in lymph nodes consist of?

Answer 53

Activated dividing B cells, with a few T cells

Question 54

What is the mantle zone in lymph nodes?

Answer 54

Resting B cells

Question 55

Function of the spleen

Answer 55

Responsible for immunological responses against blood antigens - Removes aged/defective blood cells

Question 56

2 pulp in the spleen

Answer 56

1) Red pulp 2) White pulp

Question 57

Function of red pulp in the spleen

Answer 57

Responsible for filtering blood

Question 58

Function of white pulp in the spleen

Answer 58

Immunological region of the organ

Question 59

What does MALT stand for?

Answer 59

Mucosa Associated Lymphoid Tissue