Immune System

Question 1

Intrinsict mechanisms that are poised to react immediately and thus constitute the first line of defense?

Answer 1

Innate Immunity

Question 2

Cells that recognize and destroy severely stressed or abnormal cells , such as virus-infected cells and tumor cells.

Answer 2

Natural killer Cells

Question 3

Phenomenon known to express CD 16 that confers on NK cells the ability to lyse IgG coated target cells.

Answer 3

ADDC ( Antibody Dependent Cellular Cytotoxicity)

Question 4

Consists of mechanisms that are stimulated by exposure to microbes. Mediated by lymphocytes and their products including antibodies.

Answer 4

Adaptive Immunity

Question 5

Protects against extracellular microbes and their toxins, mediated by B lymphocytes and secreted antibodies.

Answer 5

Humoral Immunity

Question 6

Responsible for defense against extracellular microbes, mediated by T lymphocytes.

Answer 6

Cell Mediated Immunity

Question 7

Mature lymphocytes that have not encountered the antigen for which they are specific.

Answer 7

Naive lymphocytes ( Immunologically Inexperienced)

Question 8

Perform the function of eliminating microbes.

Answer 8

Effector cells

Question 9

Live in a state of heightened awareness and are able to react rapidly and strongly to combat the microbe in case it returns.

Answer 9

Memory Cells

Question 10

True or False

60% of Mature T cells are CD4+

Answer 10

True

60% are CD4+
30% are CD 8+

Question 11

Stimulate B lymphocytes to make antibodies and activate other leukocytes to destroy microbes.

Answer 11

Helper T lymphocytes or CD4

Question 12

Kill infected cells and recognize cell-bound antigens only in association with class I MHC molecules.

Answer 12

Cytotoxic T lymphocytes (CTLs)

Question 13

Limit immune responses and prevent reactions against self-antigens.

Answer 13

Regulatory T lymphocytes

Question 14

Only cells in the body capable of producing antibody molecules.

Answer 14

B lymphocytes

Question 15

Most important antigen-presenting cells for initiating T-cell responses against protein antigens.

Answer 15

Dendritic cells

Question 16

Immature dendritic cells within the epidermis.

Answer 16

Langerhans cells

Question 17

Present in the germinal centers of lymphoid follicles in the spleen and lymph nodes and plays a role in humoral responses by presenting antigens to B cells in the germinal center.

Answer 17

FDC ( Follicular Dendritic Cells)

Question 18

Functions for phagocytosis and antigen presentation.

Answer 18

Macrophages

Question 19

Destroy irreversibly stressed and abnormal cells , such as virus infected cells and tumor cells.

Answer 19

NK cells (CD26, CD56)

Question 20

Where does T cells develop?

Answer 20

Thymus

Question 21

Where do B lymphocytes mature?

Answer 21

Bone marrow

Question 22

Secondary peripheral lymphoid organs. (4)

Answer 22

1. Lymph nodes
2. Spleen
3. Mucosal Lymphoid Tissues (Gastrointestinal & Respiratory tracts)
4. Cutaneous Lymphoid Tissues ( Epithelia of Skin)

Question 23

What part of the spleen T lymphocytes resides?

Answer 23

Periarteriolar lymphoid sheaths surrounding small arterioles

Question 24

What part of the spleen B lymphocytes resides?

Answer 24

Follicles ( Splenic White Pulp)

Question 25

Class I MHC ( Major Histocompatibility Complex) are recognized by what T cells?

Answer 25

CD8+ T lymphocytes

Question 26

Class II MHC ( Major Histocompatibility Complex) are recognized by what T cells?

Answer 26

CD4+ T cells

Question 27

Cells that secrete the cytokine IFN-delta, which is a potent macrophage activator.

Answer 27

TH 1 cells

Question 28

Produce IL-4 that stimulates B cells to differentiate into IgE secreting plasma cells.

Answer 28

TH2 cells

Question 29

Produce IL-5 which activates eosinophils.

Answer 29

TH2 Cells

Question 30

Secretes IL-17 that recruits neutrophils and monocytes.

Answer 30

TH17 cells

Question 31

Polysaccharides and lipids stimulate secretion of what antibody?

Answer 31

IgM

Question 32

What antibody coats / opsonize microbes and target them for phagocytosis?

Answer 32

IgG

Question 33

Antibodies that activates the Classical pathway of Complement system? (2)

Answer 33

IgG & IgM

Question 34

Secreted from mucosal epithelia and neutralizes microbes in the lumens of respiratory and gastrointestinal tracts.

Answer 34

IgA

Question 35

Antibody that cooperates to eosinophils to kill parasites, mainly by release of eosinophil granule contents that are toxic to the worms.

Answer 35

IgE

Question 36

Any substance that prompts your body to trigger an immune response against it.

Answer 36

Antigen Eg. Allergens, bacteria, virus..

Question 37

Are Y-shaped proteins produced upon detection of antigens.

Answer 37

Antibody

Question 38

In type I hypersensitivity/ Immediate hypersensitivity, injuries are caused by what antibodies? (3)

Answer 38

TH2 cells IgE antibodies Mast cells

Question 39

Can be detected in the sputum of patients with asthma.

Answer 39

Charcot-Leyden Crystals

Question 40

Type I hypersensitivity/ Immediate Hypersensitivity Reactions. (6)

Answer 40

Skin allergies Hives Allergic rhinitis Hay fever Bronchial asthma Systemic anaphylaxis

Question 41

Antibodies Responsible for Type II hypersensitivity/ Antibody-mediated Disorders?

Answer 41

IgG & IgM Interfere with normal functions or injure cells by promoting phagocytosis or lysis and inducing inflammation.

Question 42

Type II hypersensitivity/ Antibody-mediated Disorders. (4)

Answer 42

1. Transfusion reactions 2. Hemolytic Disease of the newborn ( Erythroblastosis fetalis) 3. Myasthenia gravis (Ach receptors) 4. Grave’s disease (TSH Receptor)

Question 43

Immune Complex - mediated disorder/ Type III Hypersensitivity Reaction. (3)

Answer 43

1. Arthus reaction 2. Acute serum sickness ( Administration of large amounts of foreign serum) 3. SLE

Question 44

Antibodies responsible for Immune Complex - mediated disorder/ Type III Hypersensitivity Reaction.

Answer 44

IgG and IgM Same in Type II they induce inflammation. (+) Fibrinoid necrosis

Question 45

Antibodies responsible for Cell- mediated immune disorders / Type IV hypersensitivity reactions.

Answer 45

T lymphocytes

Question 46

Immune Complex - mediated disorder/ Type III Hypersensitivity Reaction. (2)

Answer 46

1. Delayed-type hypersensitivity in tuberculin reaction. 2. CD8 + T cell Mediated Cytotoxicity - involved in **perforins and granzymes** leading to apoptosis of the target cell.

Question 47

Classical , Alternative and Lectin Pathway meets at ?

Answer 47

C3

Question 48

What are the two types of C3 convertase?

Answer 48

C4b2a & C3bBb

Question 49

Complements that cause inflammation?

Answer 49

C3a and C5a ( Aenflammation)

Question 50

Complement that functions for opsonization?

Answer 50

C3b (Bidabida )

Question 51

Complements for MAC ( Membrane attack complex) ? (5)

Answer 51

C5b ( bidabida) combines with C6-C9 to form the MAC and induce cellular lysis to infected cells.

Question 52

What are the 2 types of C5 convertase?

Answer 52

C4b2a**C3b** & C3bBb**C3b**

Question 53

What complement pathway is blocked by Meningococcal disease? (2)

Answer 53

Alternative Pathway & Lectin Pathway

Question 54

What conplement pathway is blocked by Neisseria infection?

Answer 54

MAC (C5-C9)

Question 55

What complement pathway is blocked by Bacterial infections ( pneumococcus , h. influenzae) ?

Answer 55

Classical Pathway