The immune system

Question 1

Name the components of each layer of centrifuged blood

Answer 1

Upper(“straw-coloured”) - plasma(90% water, electrolytes, proteins, lipids, sugars etc)
Middle(“white fluffy” buffy coat) - WBCs
Lower - RBCs, platelets

Question 2

What is the scientific name for white blood cells?

Answer 2

Leukocytes

Question 3

What is the scientific name for red blood cells?

Answer 3

Erythrocytes

Question 4

What is the scientific name for platelets?

Answer 4

Thrombocytes

Question 5

What cells does the common lymphoid progenitor give rise to?

Answer 5

B lymphocytes, T lymphocytes, Natural Killer cells

Question 6

What cells does the common myeloid progenitor give rise to?

Answer 6

Megakaryocytes, erythrocytes(RBCs), myeloblasts, mast cells

Question 7

What cells does the myoblast give rise to?

Answer 7

Basophils, neutrophils, eosinophils, monocytes

Question 8

What cells does the monocyte give rise to?

Answer 8

Macrophages and dendritic cells

Question 9

What do megakaryocytes give rise to?

Answer 9

Thrombocytes (platelets)

Question 10

Where are most leukocytes made?

Answer 10

Bone marrow (except T lymphocytes)

Question 11

Where are T lymphocytes made?

Answer 11

The thymus

Question 12

What is the name of the stem cell which gives rise to blood cells?

Answer 12

Multipotent haematopoietic stem cell (Or haemocytoblast)

Question 13

Name the polymorphonuclear lymphocytes

Answer 13

Neutrophils, eosinophils, basophils, mast cells(?)

Question 14

Name the mononuclear leukocytes

Answer 14

T cells, B cells, monocytes, dendritic cells, natural killer cells

Question 15

What are the soluble factors of the immune system?

Answer 15

Complement, antibodies, cytokines, chemokines

Question 16

What secretes the complement proteins?

Answer 16

The liver

Question 17

Name the 3 complement activation pathways and what they are

Answer 17

Classical - antibody binds to microbe
Alternative - complement binds to microbe
Lectin - mannose binding lectin (MBL) binds to microbe

Question 18

In infection, what are the modes of action of complement?

Answer 18

Direct lysis of microbes, attracting more leukocytes to infection site (chemotaxis), coating invading organisms (opsonisation)

Question 19

Which immunoglobulin is most abundant?

Answer 19

IgG

Question 20

Which immunoglobulin is a pentamer?

Answer 20

IgM

Question 21

Which immunoglobulins are monomers?

Answer 21

IgG, mIgM, IgA (not all), mIgD, IgE

Question 22

Where is IgM mainly found and why?

Answer 22

In the blood becasue it is too large to cross the endothelium

Question 23

Where are there high concentrations of IgA and what is it called there?

Answer 23

Mucous secretions (e.g. saliva, milk, bronchiolar and GU secretions).
Secretory IgA (sIgA)

Question 24

What is the least abundant immunoglobulin?

Answer 24

IgE

Question 25

What cells have IgE-specific receptors and readily bind to IgE?

Answer 25

Basophils and mast cells

Question 26

What responses is IgE mostly associated with?

Answer 26

Hypersensitivity allergic responses and parasitic infections

Question 27

Name the 4 types of cytokine

Answer 27

Interferons (IFN), interleukons (IL), colony stimulating factors, tumour necrosis factors (TNF)

Question 28

What do interferons do?

Answer 28

Induce a state of antiviral resistance in uninfected cells and limit the spread of viral infection

Question 29

What do interleukins do?

Answer 29

Cause cells to divide, differentiate and secrete factors

Question 30

What do colony stimulating factors do?

Answer 30

They are involved in directing the division and differentiation on bone marrow stem cells

Question 31

What do tumour necrosis factors do?

Answer 31

Mediate inflammation and cytotoxic reactions

Question 32

Give key features of innate immunity

Answer 32

Non-specific, doesn't depend on recognition by lymphocytes, instinctive, slow, present frfom birth

Question 33

What 3 parts make up innate immunity?

Answer 33

Physical and chemical barriers, phagocytotic cells, blood proteins

Question 34

Give key features of adaptive immunity

Answer 34

Responds to specific antigens, faster acting, forms memory to specific antigens, 'learned' immunity

Question 35

What is the difference between cell mediated and humoral immunity?

Answer 35

Cell mediated involves T cells to kill intracellular microbes, humoral involves B cells (plasma) producing antibodies to kill extracellular microbes

Question 36

Why are cells that recognise ‘self’ killed as they mature?

Answer 36

To prevent the immune system from attacking the body's own healthy tissues (autoimmune response)

Question 37

Innate immunity definition

Answer 37

An instinctive, non-specific protection from pathogens that is present from birth

Question 38

Adaptive immunity definition

Answer 38

A specific, acquired immunity that requires lymphocytes and antibodies

Question 39

Haematocrit definition

Answer 39

The ratio of red blood cells to total volume of blood

Question 40

Serum definition

Answer 40

Plasma without fibrinogen and other clotting factors

Question 41

Antibody/immunoglobulin definition

Answer 41

A glycoprotein in the blood produced in response to a specific antigen

Question 42

Cytokines definition

Answer 42

A number of proteins secreated by immune and non-immune cells that are important in cell signalling

Question 43

Chemokines definition

Answer 43

(Chemotactic cytokines) A small group of cytokines which can induce directed chemotaxis in nearby responsive cells