Immune System 1

Question 1

What is a pathogen?

Answer 1

Any organism with the ability to cause disease

Question 2

What are the 4 types of pathogen?

Answer 2

Bacteria

Virus

Fungi

Parasites (protozoa, worms)

Question 3

Define: Immunogen

Answer 3

a molecule that causes the immune system to make a response

Question 4

Define: antigen

Answer 4

part of immunogen that reacts with the immune effector cells or soluble antibodies

Question 5

Define: epitope

Answer 5

part of the antigen that reacts with immune effector cells or soluble antibodies

Question 6

Define: polymorphonuclear leukocyte

Answer 6

Immune cell containing granules with enzymes which are released during infection, allergic reaction of asthma.

Examples: oesinophils, neutrophils, basophils

Question 7

What are the two (immune) cell classes found in bone marrow?

Answer 7

Myeloid cells

Lymphoid cells

Question 8

Name 1 cell from each category of myeloid cells

Answer 8

1) Antigen presenting cells:
monocyte, macrophage, dendritic cell

2) Polymorphonuclear leukocytes:
basophil, neutrophil, oesinophil

3) mast cell

Question 9

Which are the small lymphocytes?

Answer 9

B cells

T cells

Question 10

Which are the large lymphocytes?

Answer 10

NK cells

NK = natural killer

Question 11

Name the TWO primary lymphoid organs.

Answer 11

Bone marrow

Thymus

Question 12

Name the SIX secondary lymphoid organs.

Answer 12

Spleen

Adenoids

Tonsils

Appendix

Lymph nodes

Peyer’s patches

Question 13

Where do B cells originate and mature?

Answer 13

Bone marrow

Question 14

Which cells originate in the BONE MARROW?

Answer 14

B cells - mature in it

T cells - leave immature

Question 15

Where is the THYMUS located?

Answer 15

Just above the heart

Question 16

Where do T cells migrate to mature ?

Answer 16

Migrate from bone marrow to the THYMUS to mature

Progress from cortex to medulla during differentiation

Question 17

In which sites do mature lymphocytes activate in response to invading pathogens?

Answer 17

Secondary lymphoid tissues

Question 18

Where do lymph nodes lie?

Answer 18

At the junction of the network of LYMPHATIC VESSELS

Question 19

What is the role of lymphatic vessels ?

Answer 19

• They collect the plasma fluid (lymph) which continuously leaks from blood vessels
• Lymph (fluid) returns to the blood vessles via the thoracic duct

Question 20

What is the largest lymphatic vessel in the human body?

Answer 20

Thoracic duct

75% of the body’s lymph (fluid) passes through it

Question 21

How do lymphocytes meet the pathogen?

Answer 21

Move from capillaries –> lymph nodes to meet pathogen

Question 22

What are lymphocytes?

Answer 22

A type of immune cell.
(Lymphocytes consist of B- T- and NK- cells)

Others include macrophages/monocytes, neutrophils

THESe ARE ALL TYPES OF WBCs!

Question 23

Which cells in immune system produce variable, slow and highly specific immune response?

Answer 23

Lymphocytes

Question 24

What is part of the immediate innate response ?

Answer 24

Defensins

Complement

Question 25

What are the responses derived from complement activation?

Answer 25

Opsonisation Inflammation Lysis of pathogen Activation of B cell

Question 26

Which 3 factors are part of the innate immune response?

Answer 26

Barriers Antimicrobial peptides Complement system

Question 27

Name the 4 antimicrobial peptides

Answer 27

Histatins Cathelicidins Defensins Lectins

Question 28

Which antimicrobial peptide is produced in the oral cavity and is involved in wound healing of the oral cavity

Answer 28

Histatins (short histidine peptides)

Question 29

Which antimicrobial peptide is against fungi?

Answer 29

Histatins

Question 30

Which antimicrobial peptides are against bacteria only? | 2 items

Answer 30

Cathelicidins Lectin

Question 31

Which antimicrobial peptide is against both fungi and bacteria? (1 item)

Answer 31

Defensins

Question 32

Which antimicrobial peptides are against viruses ? (2 items)

Answer 32

SOME defensine SOME histidines

Question 33

Are neutrophils long or short lived?

Answer 33

Short lived

Question 34

Are macrophages antigen presenting cells or not

Answer 34

Antigen presenting cell

Question 35

Do neutrophils present early or late in the infection?

Answer 35

Early

Question 36

Do macrophages present early or late in the infection?

Answer 36

Late

Question 37

Where can neutrophils and macrophages be found?

Answer 37

N: Blood and tissues M: Tissues only

Question 38

Which type of immunity are neutrophils and macrophages respectively involved in?

Answer 38

N: innate immunity M: innate and adaptive immunity

Question 39

Are macrophages long or short lived?

Answer 39

Long lived

Question 40

Molecular weight of cytokines

Answer 40

5-25 kDa

Question 41

3 roles of cytokines in the induced innate immune response?

Answer 41

1. Mediate + regulate innate immunity - by neutrophils and macrophages 2. Medicate + regulate adaptive immunity - by T lymphocytes 3. Stimulate haematopoiesis - by bone marrow in stromal cells

Question 42

What is the main feature involved in the lysis of a pathogen (complement system)

Answer 42

Membrane attack complex (MAC)

Question 43

What is the main feature involved in opsonisation (complement system)

Answer 43

phagocytosis

Question 44

What is the main feature involved in inflammation (complement system)

Answer 44

small fragments of complement (C3a and C5a)

Question 45

What are the two major opsonin proteins?

Answer 45

Antibodies (main: IgG) C3b (fragment molecule of the complement system)

Question 46

Role of opsonins

Answer 46

Enhance the phagocytosis of pathogens by making them more "tasty" for phagocytes to engulf

Question 47

In phagocytosis, how are the pathogens killed and degraded?

Answer 47

Through the ROS and RNS derived from NO or Lysosomal enzymes e.g. elastase, lysosyme.

Question 48

Which cytokines induce fever to reduce bacterial/viral replication?

Answer 48

IL-1 IL-6 TNF-alpha

Question 49

What do monocytes differentiate to when they move from blood to tissues?

Answer 49

Macrophages