The Immune System

Question 1

Name three functions of circulating blood.

Answer 1

Regulation, transportation, protection.

Question 2

What is Hematopoiesis?

Answer 2

The production of blood cells from pluripotent stem cells.

Question 3

Where does hematopoiesis occur?

Answer 3

Within the bone marrow.

Question 4

What do lymphoid stem cells give rise to?

Answer 4

Lymphocytes

Question 5

What do myeloid stem cells give rise to?

Answer 5

All other blood cells

Question 6

What two things regulate hematopoiesis?

Answer 6

Cytokines and growth factors.

Question 7

Give the proper name for a red blood cell.

Answer 7

Erythrocyte

Question 8

How are erythrocytes formed?

Answer 8

When blood O2 levels drop, the hormone erythropoietin stimulates production of erythrocytes.

Question 9

What is the proper name for erythrocyte production?

Answer 9

Erythropoiesis

Question 10

How many erythrocytes are there per microliter of blood?

Answer 10

Approx. 5 million

Question 11

What does the term HEMATOCRIT refer to?

Answer 11

The proportion of total blood volume occupied by red blood cells.

Question 12

What do mature mammalian erythrocytes lack?

Answer 12

Nuclei

Question 13

Name the pigment within erythrocytes that binds and transports O2.

Answer 13

Haemoglobin

Question 14

Give the proper name for a white blood cell.

Answer 14

Leukocyte

Question 15

What proportion of the cells in human blood are leukocytes?

Answer 15

Less than 1%

Question 16

Which is larger, an erythrocyte or a leukocyte?

Answer 16

Leukocyte

Question 17

Do leukocytes have nuclei?

Answer 17

YES

Question 18

Name the two types of leukocytes.

Answer 18

Granular and Agranular

Question 19

Give three examples of granular leukocytes.

Answer 19

Neutrophils, eosinophils, basophils.

Question 20

Give two examples of agranular leukocytes.

Answer 20

Monocytes, lymphocytes.

Question 21

Which type of blood cell is involved in immune responses?

Answer 21

Leukocytes

Question 22

What are the two components within the immune system?

Answer 22

Cells and Humoral Components

Question 23

Name the three cell types involved in the immune system.

Answer 23

Lymphocytes, granulocytes and macrophages.

Question 24

Name the humoral components of the immune system.

Answer 24

Antibodies, complement and cytokines.

Question 25

Describe the two ways in which pathogens are destroyed.

Answer 25

Small pathogens can be phagocytosed (engulfed) by WBC's. Larger pathogens require cytotoxic products to be secreted and targeted at them.

Question 26

Why are intracellular pathogens more difficult to find and destroy?

Answer 26

They can 'hide' within host cells.

Question 27

If a host cell becomes infected with parasites, what happens?

Answer 27

The host cell is destroyed.

Question 28

Put the five pathogen classes into size order.

Answer 28

Worms, Protozoa, Fungi, Bacteria, Viruses

Question 29

Name the three basic prokaryotic cell shapes.

Answer 29

Bacillus (rod), coccus (sphere) and spirillum (helix).

Question 30

Give the defining features of a gram positive bacteria.

Answer 30

Thick, complex network of peptidoglycan. | Contains lipoteichoic and teichoic acid.

Question 31

Give the defining features of a gram negative bacteria.

Answer 31

Thin layer of peptidoglycan. Second outer membrane with lipopolysaccharide. Resistant to many antibiotics.

Question 32

Which type of bacteria (gram neg/pos) is resistant to many antibiotics?

Answer 32

Gram negative.

Question 33

Give the defining features of the S-layer.

Answer 33

Rigid paracrystalline layer found in some archaea/bacteria. Present outside of peptidoglycan/outer membrane in gram pos/neg. bacteria. Diverse functions, often involves adhesion.

Question 34

Give the defining features of the capsule in bacteria.

Answer 34

Gelatinous layer found in some bacteria. | Aids attachment. Protects from immune system.

Question 35

In the west, what % of deaths are caused by infection?

Answer 35

Less than 2%.

Question 36

In developing countries, what % of deaths are caused by infection?

Answer 36

70-80%

Question 37

What three things are essential for the immune system to be effective?

Answer 37

Distinguish between self and non-self, rapid activation, cytotoxic potential against range of pathogens.

Question 38

Outline the main features of innate immunity.

Answer 38

Recognition of invading pathogens, rapid response, uses soluble antimicrobial proteins.

Question 39

Outline the main features of adaptive immunity.

Answer 39

Genetic rearrangements that generate a diverse range of molecules to recognise ANY invader, SLOWER response but HIGHLY SPECIFIC.

Question 40

What features make skin an invaluable part of our innate immunity?

Answer 40

Impenetrable to gases and liquids. Reinforced with chemicals. Sweat and oil glands give it a pH of 3-5. Lysozyme in sweat breaks down bacterial cell walls.

Question 41

How do the non-pathogenic bacteria that inhabit our skin help prevent infection?

Answer 41

They out-compete invading pathogenic micro-organisms.

Question 42

Name the three membrane lined tracts which are potential routes of infection?

Answer 42

Digestive, respiratory and urogenital tracts.

Question 43

What defensive mechanisms does the digestive tract have?

Answer 43

Salivary lysozymes, acidic stomach environment, normal flora to outcompete pathogens.

Question 44

What defensive mechanisms does the respiratory tract have?

Answer 44

Ciliary action (cilia waft pathogens upwards to be swallowed).

Question 45

What defensive mechanisms does the urogenital tract have?

Answer 45

Acidic urine, normal flora to outcompete pathogens.

Question 46

In addition to combating infection, name three others areas that the immune system is involved in.

Answer 46

Allergies and allergic reactions. Cancer. Transplants.

Question 47

What is the most abundant type of granulocyte?

Answer 47

Neutrophil

Question 48

Innate immunity relies upon molecular patterns on pathogens being recognised. What are the two types of pattern?

Answer 48

PAMP - pathogen-associated molecular pattern. | MAMP - microbe-associated molecular pattern.

Question 49

What are PAMP's and MAMP's recognised by?

Answer 49

PRR's - pattern recognition receptors

Question 50

Where are PRR's located?

Answer 50

Either soluble, or located on the surface of blood cells.

Question 51

Give an example of a PRR?

Answer 51

Toll-Like receptors (mainly studied in Drosophila)

Question 52

What is opsonisation?

Answer 52

A process by which pathogens are marked for ingestion and destruction by phagocytes.

Question 53

Describe the process of opsonisation.

Answer 53

Pathogen coated with opsonic proteins. These are recognised by opsonic receptors on phagocytes that act as a bridge. Pathogen is then engulfed.

Question 54

Give three examples of opsonic proteins.

Answer 54

Complement fragments, immunogobins, acute phase proteins.

Question 55

Give two examples of opsonic receptors.

Answer 55

Complement receptors, immunoglobin receptors.

Question 56

What does the phagocyte opsonic receptor FcR recognise?

Answer 56

Portions of antibody molecules.

Question 57

What does the phagocyte opsonic receptor CR recognise?

Answer 57

Portions of complement proteins.

Question 58

Name four non-specific defensive molecules utilised in an innate immune response.

Answer 58

Defensins, proteases, interferons and reactive oxygen species (H2O2 and HOCl).