Lymphoid System

Question 1

It is the key cell involved in the immune response.

Answer 1

Lymphoid system

Question 2

How many percent does lymphocytes represent in circulating white blood cells.

Answer 2

20 and 40 percent

Question 3

B cells develop their identifying characteristics.

Answer 3

Bone marrow

Question 4

Largest tissue of the body (1300-1500)g in the adult.

Answer 4

Bone marrow

Question 5

Fills the core of all long bones and is the main source of hematopoietic stem cells.

Answer 5

Bone marrow

Question 6

T cells develop their identifying characteristics.

Answer 6

Thymus

Question 7

In humans, it weighs an average of 30 g at birth, reaches about 35 g at puberty, and then gradually atrophies.

Answer 7

Thymus

Question 8

Major organ of antibody synthesis.

Answer 8

Spleen

Question 9

Large discriminating filter, as it removes old and damaged cells and foreign antigens from the blood.

Answer 9

Spleen

Question 10

Largest secondary lymphoid organ, having a length of approximately 12 cm and weighing 150 g in the adult.

Answer 10

Spleen

Question 11

Consist of RED PULP & WHITE PULP.

Answer 11

Spleen

Question 12

Central COLLECTING POINTS FOR LYMPH FLUID from adjacent tissues.

[secondary lymphoid organs]

Answer 12

Lymph nodes

Question 13

Outer porion

[lymph nodes]

Answer 13

Cortex

Question 14

Region between follicles and medulla.

Answer 14

Para - cortex

Question 15

Inner portion

Answer 15

Medulla

Question 16

Found in the gastrointestinal, respiratory, and urogenital tracts.

[secondary lymphoid organs]

Answer 16

Mucosal - Associated Lymphoid Tissue (MALT)

Question 17

Specialized type of MALT:

Answer 17

Peyer’s Patches in the intestines

Question 18

Epidermis contains a number of intra epidermal lymphocytes.

[secondary lymphoid organs]

Answer 18

Cutaneous - Associated Lymphoid Tissue (CALT)

Question 19

Found in the mucous membrane lining of the oral and pharyngeal cavities.

[secondary lymphoid organs]

Answer 19

Tonsils

Question 20

High concentration of lymphocytes.

[secondary lymphoid organs]

Answer 20

Appendix

Question 21

Family of mononuclear, nonphagocytic white blood cells found in the blood, lymph, and lymphoid tissues.

[primary lymphoid cell]

Answer 21

Lymphocyte

Question 22

They are responsible for humoral and cellular immunity and tumor surveillance.

[primary lymphoid cell]

Answer 22

Lymphocyte

Question 23

B and T lymphocytes, NK cells.

Answer 23

Lymphocyte

Question 24

Lymphocyte precursors called ______ thymus from the bone marrow.

Answer 24

Thymocytes

Question 25

for growth and differentiation.

Answer 25

IL - 7

Question 26

Two immunologic functions: [overview of t-cell differentiation]

Answer 26

1. Effector functions 2. Regulatory functions

Question 27

Cytolysis of virally infected cells & tumor targets; production of lymphokine. [immunologic functions]

Answer 27

Effector functions

Question 28

Ability to amplify or suppress other effector lymphocytes (including T and B cells) [immunologic functions]

Answer 28

Regulatory functions

Question 29

Sheep RBC receptor, the classical T cell surface marker. [t cells]

Answer 29

CD 2

Question 30

Part of T-cell antigen-receptor complex. [t cells]

Answer 30

CD 3

Question 31

Receptor for MHC class II molecule.

Answer 31

CD 4

Question 32

Receptor for MHC class I molecule.

Answer 32

CD 8

Question 33

Early Thymocyte lack CD4 and CD8 markers, which are important to their later function. [stages in T cell differentiation]

Answer 33

Double negative stage

Question 34

2 chains express in double-negative stage.

Answer 34

1. gamma (γ) 2. delta (δ)

Question 35

Random rearrangement of the genes that code for the antigen receptor known as TCR begins at this stage CD3. [stages in T cell differentiation]

Answer 35

Double negative stage

Question 36

Thymocytes express both CD4 and CD8 antigens. [stages in T cell differentiation]

Answer 36

Double positive stage

Question 37

Double positive thymocytes proliferate and then begin to rearrange the genes coding for the alpha chain. [stages in T cell differentiation]

Answer 37

Double positive stage

Question 38

The CD3-αβreceptor complex (TCR) is expressed on cell surface. [stages in T cell differentiation]

Answer 38

Double positive stage

Question 39

Process takes place that allows only double-positive cells with functional TCR receptors to survive. [double positive stage]

Answer 39

Positive selection

Question 40

Takes place among the surviving double-positive T cells. [double positive stage]

Answer 40

Negative selection

Question 41

Immune response is known as cell-mediated immunity. [stages in T- cell differentiation]

Answer 41

Sensitized T cells stage

Question 42

Where B cells is generated?

Answer 42

Bone marrow

Question 43

Takes 1-2 weeks to develop from hematopoietic stem cell.

Answer 43

B cells

Question 44

B cell life span

Answer 44

3-5 days

Question 45

Originally found to mature in birds in an organ called “bursa of fabricus” which is similar to appendix of humans.

Answer 45

B-cell

Question 46

Surface immunoglobulin: traditional marker.

Answer 46

B-cells

Question 47

Surface immunoglobin of B-cell

Answer 47

B-cell

Question 48

CD19,20,21: newest marker

Answer 48

B-cell

Question 49

Progenitors [stages in B-CELL differentiation]

Answer 49

Pro-B cells stage

Question 50

Rearrangement of chromosome 14 to form heavy chain part of the antibody molecule. [stages in B-CELL differentiation]

Answer 50

Pro - B cells stage

Question 51

No surface immunoglobulin. [stages in B-CELL differentiation]

Answer 51

Pro - B cells stage

Question 52

CD 19, CD45 (+) [stages in B-CELL differentiation]

Answer 52

Pro - B cells stage

Question 53

Precursors [stages in B-CELL differentiation]

Answer 53

Pre-B cells stage

Question 54

Synthesis of the heavy chain occurs à IgM (accumulates in the cytoplasm) [stages in B-CELL differentiation]

Answer 54

Pre - B cells stage

Question 55

May also express μ chains on the cell surface, accompanied by an unusual light chain molecule called a SURROGATE LIGHT CHAIN. [stages in B-CELL differentiation]

Answer 55

Pre - B cells stage

Question 56

Appearance of complete IgM molecules on cell surface. [stages in B-CELL differentiation]

Answer 56

Immature B cells stage

Question 57

Rearrangement of gene to form light chain on either chromosome 2 (kappa), or 22 (lambda). [stages in B-CELL differentiation]

Answer 57

Immature B cells stage

Question 58

CD21, CD40, MHC Class II (+) [stages in B-CELL differentiation]

Answer 58

Immature B cells stage

Question 59

[2] Spleen in Mature B Cells stage

Answer 59

1. Marginal B 2. Follicular B

Question 60

Cells remain in the spleen in order to respond quickly to any blood-borne pathogens they may come into contact with. [spleen][immature b cells stage]

Answer 60

Marginal B

Question 61

Antigen-dependent activation of B cells takes place in the primary follicles of peripheral lymphoid tissue.

Answer 61

Activated B cells stage

Question 62

Exhibit identifying markers that include CD25. [stages in B-CELL differentiation]

Answer 62

Activated B cells stage

Question 63

When B cells are activated in this manner, they transform into blasts that will give rise to both plasma cells and so-called memory cells. [stages in B-CELL differentiation]

Answer 63

Activated B cells stage

Question 64

Found in blood (60 - 80% circulating lymphocytes), thoracic fluid, lymph nodes. [cells]

Answer 64

T cells

Question 65

Identified by "rosette" formation with SRBCs. [cells]

Answer 65

T cells

Question 66

End products of activation are cytokines. [cells]

Answer 66

T cells

Question 67

Antigens include CD2, CD3, CD4, CD8. [cells]

Answer 67

T cells

Question 68

Located in paracortical region of lymph nodes. [cells]

Answer 68

T cells

Question 69

Identified by surface immunoglobulin. [cells]

Answer 69

B cells

Question 70

End product of activation is antibody. [cells]

Answer 70

B cells

Question 71

Natural Killer Cells also known as?

Answer 71

Large Granular Lymphocytes (LGLs)

Question 72

These lymphocytes are generally larger than cells and B cells at approximately 15 μm in diameter, and they contain kidney shaped nuclei with condensed chromatin and prominent nucleoli.

Answer 72

Natural Killer Cell

Question 73

Are able to lyse virally infected cells and tumor cells without prior immunization/exposure.

Answer 73

Natural Killer Cells

Question 74

Surface marker: [natural killer cell]

Answer 74

CD16, CD56

Question 75

Development: [natural killer cell]

Answer 75

IL - 15

Question 76

Stimulated by: [natural killer cells]

Answer 76

IL-12, INF γ & β

Question 77

Half life: [natural killer cells]

Answer 77

7 to 10 days

Question 78

[2] Methods/ways of killing - Natural killer cells

Answer 78

1.Inhibitory signals 2. Antibody dependent cell cytotoxicity (ADCC)

Question 79

If NK cells react with MHC class I proteins, then inhibition of natural killing occurs. [nk cells] [methods/ways of killing]

Answer 79

Inhibitory signals

Question 80

It is based on recognition of MHC Class I protein, which is expressed on all healthy cells. [nk cells] [methods/ways of killing]

Answer 80

Inhibitory signals

Question 81

Examples of inhibitory receptors found in NK cells. [nk cells] [methods/ways of killing]

Answer 81

Killer cell Immunoglobulin-like receptors (KIRs) and CD94/NKG2A

Question 82

NK cells recognize and lyse antibody-coated cells through a process called antibody dependent cell cytotoxicity. [nk cells] [methods/ways of killing]

Answer 82

Antibody dependent cell cytotoxicity.

Question 83

Recognize antigen along with MHC class II protein. [mature T cells stage]

Answer 83

CD4 + T cells

Question 84

Also termed as "HELPER" or "INDUCER CELLS". [mature T cells stage]

Answer 84

CD4+ T cells

Question 85

Approximately 2/3 of peripheral T cells express CD4 antigen. [mature T cells stage]

Answer 85

CD4+ T cells

Question 86

produce (IFN-γ) & (TNF-β) [CD4+]

Answer 86

Th1 cells

Question 87

Produce interleukins, including IL-4, IL-5, IL-10, and IL-13. [CD4+]

Answer 87

Th2 cells

Question 88

Interact with antigen and MHC class I proteins. [mature T cells stage]

Answer 88

CD8+ T cells

Question 89

Population consists of cytotoxic T cells. [mature T cells stage]

Answer 89

CD8+ T cells

Question 90

Remaining one-third express CD8 antigen. [mature T cells stage]

Answer 90

CD8+ T cells

Question 91

Possess the CD4 antigen and CD25. [mature T cells stage]

Answer 91

T Regulatory Cells (T reg)

Question 92

These cells comprise approximately 5 to 10 percent of all CD4-positive T cells. [mature T cells stage]

Answer 92

T Regulatory Cells (T reg)

Question 93

Play an important role in suppressing the immune response to self-antigens. [mature T cells stage]

Answer 93

T Regulatory Cells (T reg)

Question 94

T cells exposed to antigen. [stages in T-cell differentiation]

Answer 94

Activated T - Cells Stage

Question 95

Activated T lymphocytes express receptors IL-2. [stages in T-cell differentiation]

Answer 95

Activated T - Cells Stage

Question 96

T lymphoblasts differentiate into functionally active small lymphocytes that produce cytokines/lymphokines. [stages in T-cell differentiation]

Answer 96

Sensitized T - Cells Stage

Question 97

Early precursor of T-cell

Answer 97

Cortex

Question 98

Mature T cell

Answer 98

Medulla

Question 99

Normal ratio of CD4+ : CD8+ cells:

Answer 99

2:1

Question 100

In HIV, ratio of CD4+ : CD8+ cells:

Answer 100

0:5:1

Question 101

Normal CD4+ cell count:

Answer 101

500 - 1300 cells/ mm3

Question 102

AIDS, CD4+ cell count:

Answer 102

<200 cells/ mm3

Question 103

CD 25 (+) is the receptor for IL-2. [stages in T-cell differentiation]

Answer 103

Activated T Cells Stage

Question 104

It is the receptor for IL-2 in activated T-cell stage.

Answer 104

CD 25 (+)

Question 105

Also known as central lymphoid organ; SITE OF MATURATION and differentiation, growth and development.

Answer 105

Primary lymphoid organs

Question 106

Also known as peripheral lymphoid organ; acts as TRAPPING SITE, standby area of T-cell and B-cell, and place of encounter; site of antigen dependent lymphopoiesis.

Answer 106

Secondary lymphoid organs

Question 107

Culling and pitting of old RBCs. [spleen]

Answer 107

Red pulp

Question 108

contains lymphoid tissue [spleen]

Answer 108

White pulp