The Immune System

Question 1

What are the 4 main functions of the immune system

Answer 1

Protect, recognise self/ non self , attack and destroy

Question 2

What are the 2 main arms of the immune system

Answer 2

Innate and acquired arms

Question 3

What is the innate arm of the immune system

Answer 3

Natural immunity that we are born with and is the same in everyone

Question 4

What is the acquired arm of the immune system

Answer 4

Immunity recruited over a lifetime that is different between individuals due to different exposures

Question 5

Which arm of the immune system has a non-specific immune response (attacks the same way every time)

Answer 5

Innate immunity

Question 6

Which arm of the immune system has a pathogen and antigen specific response

Answer 6

Acquired immunity

Question 7

Which arm of the immune system has a lag time between exposure and maximal response

Answer 7

Acquired immunity

Question 8

Which arm of the immune system has no immunological memory

Answer 8

The innate arm

Question 9

Which arm of the immune system is only found in jawed vertebrates

Answer 9

Acquired

Question 10

Which arm of the immune system leads to immunological memory

Answer 10

Acquired arm

Question 11

Why might the innate arm activate the acquired arm of the immune system

Answer 11

As innate response may not be specific enough to overcome infection alone

Question 12

What are the 2 categories of leukocytes (WBC)

Answer 12

Granuocytes and agranulocytes

Question 13

What is the difference between agranulocytes and granulocytes

Answer 13

Granulocytes has granules in their cytoplasm, agranulocytes do not

Question 14

What are the 3 types of granulocytes

Answer 14

Neutrophil, eosinophil and basophil

Question 15

What are the 2 types of agranulocytes

Answer 15

Lymphocytes and monocytes

Question 16

What is the main function of neutrophils

Answer 16

Phagocytosis

Question 17

What % of leukocytes are granulocytes

Answer 17

60-70%

Question 18

What % of granulocytes are neutrophils

Answer 18

> 90%

Question 19

What are the 3 main cells of the innate immune system

Answer 19

Neutrophils, monocytes/macrophages, natural killer cells

Question 20

What percentage of all leukocytes are neutrophils

Answer 20

50-70%

Question 21

Where are neutrophils found

Answer 21

Mostly in bone marrow, some in circulation and vascular pools

Question 22

What is the lifespan of neutrophils in blood

Answer 22

5-6 days

Question 23

What is the lifespan of neutrophils in tissue

Answer 23

2-3 days

Question 24

Which type of innate immune cell is polymorphonuclear/PMNS (nucleus has multiple lifes)

Answer 24

Neutrophils

Question 25

What is phagocytosis

Answer 25

The process of ingestion of bacteria, virus or cell debris

Question 26

Where does phagocytosis occur

Answer 26

In tissues

Question 27

Describe phagocytosis

Answer 27

Neutrophil moves to antigen, open up and engulfs in vacuole

Question 28

Describe the killing process following phagocytosis

Answer 28

Granules move to and fuse with vacuole containing antigen/pathogen etc Degranulation as granules release contents to degrade antigens respiratory burst Products of degradation are released as vacuole opens back up Neutrophils then degrade themselves

Question 29

What are monocytes/macrophages

Answer 29

Agranulocytes that express pattern recognition receptors (PRR) called Toll-like receptors (TLR) which recognise pathogen associated molecular patterns (PAMPS)

Question 30

What activates monocytes/macrophages

Answer 30

Binding to TLR (Toll-like receptors)

Question 31

What are the functions of monocytes/macrophages

Answer 31

Phagocytosis, release of messenger substances (cytokines) to communicate with other cells, APC (antigen presenting cells) for communication with acquired arm

Question 32

What is the difference between monocytes and macrophages

Answer 32

Monocytes are agranulocytes that circulate the blood and macrophages are agranulocytes once in the tissue (change shape between locations)

Question 33

What are natural killer cells

Answer 33

Large granular lymphocytes that are intracellular killing cells that destroy a variety of tumour and virus infected cells without the need to recognise the foreign matter to attack

Question 34

How to natural killer cells destroy infected cells

Answer 34

Bind to surface of infected cells without and release performin which activates apoptosis (cell suicide)

Question 35

What are the 2 main cells of the acquired immune system

Answer 35

T-lymphocytes and B-lymphocytes

Question 36

How does the innate arm communicate with the acquired arm of the immune system

Answer 36

Via antigen presenting cells e.g. macrophages/monocytes that display the invading antigen to the acquired arm to activate it

Question 37

How to APC display antigens

Answer 37

By incorporating the antigen protein into their cell surface and forming a major histocompatibility complex (MCH) II

Question 38

Which type of lymphocyte mature in the thymus

Answer 38

T-cells

Question 39

Which type of lymphocyte are part of the humoral (extracellular) response

Answer 39

B cells

Question 40

Where do B cells mature

Answer 40

Bone marrow

Question 41

Which type of lymphocyte produce memory cells

Answer 41

Both T and B- cells

Question 42

Which type of lymphocyte makes up the majority of lymphocytes (60-70%)

Answer 42

T-cells

Question 43

Which type of lymphocyte has a cell-mediated (intracellular) response

Answer 43

T-cells

Question 44

What are the 3 subsets of T-cells

Answer 44

T-helper, T-cytotoxic and T-regulatory

Question 45

What is the function of the T helper subset

Answer 45

Orchestrates and coordinates the immune response by meeting APC and recognising the displayed antigen

Question 46

What is the function of the T cytotoxic subset

Answer 46

Binds to and kills antigen specific infected cells by releasing perfornin

Question 47

What is the function of the T regulatory subset

Answer 47

Help to regulate/ switch off the immune response to avoid chronic inflammation (damage to healthy tissue post immune response)

Question 48

What are the two different responses of T-cells

Answer 48

Type 1 (TH1) and Type 2 T-cells (TH2)

Question 49

What if the functional difference between Type 1 and 2 T cells

Answer 49

Release different types of cytokines

Question 50

What does Type 1 T cells promote

Answer 50

Cell-mediated immunity (defence against intracellular pathogens)

Question 51

What does Type 2 T cells promote

Answer 51

Humoral (antibody) immunity (defence against extracellular pathogens)

Question 52

What are the 2 types cells produced by B-cells

Answer 52

Plasma cells and memory cells

Question 53

How are T-cells indirectly involved in the humoral response

Answer 53

T-cells cannot affect pathogens that can survive outside of the cell so instead are part of the initial process by signalling a humoral response is needed

Question 54

What are plasma cells

Answer 54

Cells that secrete immunoglobulin/antibody specific to an antigen

Question 55

What are the function of immunoglobins/antibodies

Answer 55

Cannot directly kill the antigen but binding to it to prevent it binding elsewhere and causing further damage Can also signal to other cells to come and kill or agglutinate to slow cell

Question 56

What are the 2 response of the acquired immune system

Answer 56

Cell mediated and humoral

Question 57

What is leukocytosis

Answer 57

Increase in the number of leukocytes circulating blood

Question 58

Which types of leukocytes predominantly increase during leukocytosis

Answer 58

Neutrophils and lymphocytes

Question 59

What is leukocytosis a response to

Answer 59

Exercise

Question 60

What is leukocytosis dependent on during brief exercise (<1 hour)

Answer 60

Intensity

Question 61

What is delayed leukocytosis

Answer 61

A second increase following exercise 2-4 hours later

Question 62

Why is the leukocytosis produced by prolonged endurance exercise greater than short term exercise

Answer 62

As delayed leukocytosis occurs whilst exercise is still being performed (super imposed response)

Question 63

What is the difference between leukocytosis and delayed leukocytosis

Answer 63

Delayed is solely due to an increase in neutrophil number

Question 64

How can inadequate nutrition directly affect immune function

Answer 64

Altered nutritent availability / co enzyme/ cofactors involved in immune cell energy, metabolism and protein synthesis

Question 65

How does inadequate nutrition indirectly affect immune function

Answer 65

Altered hormone response/ immune regulatory effects of stress hormones

Question 66

What can cause low grade chronic inflammation (leading to non communicable diseases)

Answer 66

Positive energy balance