Cells and Organs Involves in Adaptive Immunity

Question 1

Antigen-specific B-cell receptors (BCRs)

Secrete antibody

Humoral immunity

Answer 1

B cells

Question 2

Antigen-specific T-cell receptors (TCRs)

T-cells subsets and cytokines

Cellular immunity

Answer 2

T cells

Question 3

_____ exhibit antigen specificity by virtue of their expression of antigen-specific T-cell receptors (TCRs).

Answer 3

T cells

Question 4

In the case of T-cells, their participation in adaptive immune responses is as varied as the T-cell subsets and _____ they produce.

Answer 4

cytokines

Question 5

Historically, T-cell mediated responses have been
referred to as ______

Answer 5

cell-mediated responses or cellular
immunity

Question 6

B cells expressing antigen-specific B-cell receptors (BCRs) synthesize and secrete antibody into the bloodstream. This is often termed ______

Answer 6

humoral immunity

Question 7

primary lymphoid organs:

Answer 7

bone marrow
thymus

Question 8

Considered the largest tissue of the body, with a total weight of 1300 - 1500g in the adult

Answer 8

bone marrow

Question 9

Fills the core the all long bones and is the main source of hematopoietic stem cells of the blood cell lines

Answer 9

bone marrow

Question 10

T,B,and NK cells arise from a common precursor:

Answer 10

common lymphoid precursor (CLP)

Question 11

The center for antigen independent lymphopoiesis

Answer 11

bone marrow

Question 12

Site of T cells maturation

Answer 12

thymus

Question 13

A small, flat, bilobed organ found on the thorax, weighs an average of 30 g at birth, reaches about 35 g at puberty, and then gradually atrophies

Answer 13

thymus

Question 14

SECONDARY LYMPHOID ORGANS:

Answer 14

Spleen, lymph nodes, tonsils, appendix, Peyer’s patches in the intestines, and other mucosal-
associated lymphoid tissue (MALT)

Question 15

Once differentiation occurs, mature T and B lymphocytes are released from the bone marrow and the thymus. They migrate to _____ and become part of a
recirculating pool.

Answer 15

secondary lymphoid organs

Question 16

_____ where activation of lymphocytes occurs on these organs

Answer 16

lymphopoiesis

Question 17

Largest secondary lymphoid organ, approx. 12 cm and weighing 150 g in adult

Answer 17

spleen

Question 18

Located in the upper-left quadrant of the abdomen

Answer 18

spleen

Question 19

A large discriminating filter, as it removes old and damaged cells and foreign antigens from the blood

Answer 19

spleen

Question 20

makes up >1/2 of the total vol.; function is to destroy old RBCs

Answer 20

red pulp

Question 21

approx. 20% of total wt. of spleen and contains the lymphoid tissue

Answer 21

white pulp

Question 22

Located along lymphatic ducts and serve as central collecting points for lymph fluid from adjacent tissues

Answer 22

lymph nodes

Question 23

primary function of lymph nodes:

Answer 23

Generation of B-cell memory

Question 24

Accumulation of lymphocytes and other cells causes the lymph nodes to become enlarged, a condition known as ______

Answer 24

lymphodenopathy

Question 25

The outermost layer, the _____, contains macrophages and aggregations of B cells in primary follicles similar to those found in the spleen.

Answer 25

cortex

Question 26

These are the mature, resting B cells that have not yet been exposed to antigen

Answer 26

cortex

Question 27

Specialized cells called _____ are also located here. They are found only in lymphoid follicles and have long cytoplasmic processes that radiate out like tentacles. These cells exhibit a large number of receptors for antibody and complement and help to capture antigen to present to T and B cells.

Answer 27

follicular dendritic cells

Question 28

consist of antigen-stimulated proliferating B cells.

Answer 28

secondary follicles

Question 29

The interior of a secondary follicle is known as ______, because it is here that blast transformation of the B cells takes place

Answer 29

the germinal center

Question 30

Plasma cells, which actively secrete antibody, and memory cells, which are just a step away from forming plasma cells, are present. generation of _____ is a primary function of lymph nodes.

Answer 30

B-cell memory

Question 31

T lymphocytes are mainly localized in the ____

Answer 31

paracortex

Question 32

T lymphocytes are in close proximity to antigen-presenting cells called _____

Answer 32

interdigitating cells

Question 33

The medulla is ______ but contains some T cells (in addition to B cells), macrophages, and numerous plasma cells.

Answer 33

less densely populated

Question 34

Found in the gastrointestinal, respiratory, and urogenital tracts

Answer 34

Mucosal-Associated Lymphoid Tissue (MALT)

Question 35

Here, macrophages and lymphocytes are localized at some of the main ports of entry for foreign organisms.

Answer 35

Mucosal-Associated Lymphoid Tissue (MALT)

Question 36

represent a specialized type of MALT and are located at the lower ileum of the intestinal tract

Answer 36

Peyer’s patches

Question 37

Found in the mucous membrane lining of the oral and pharyngeal cavities Their function is to respond to pathogens entering the respiratory and alimentary tracts

Answer 37

Tonsils and Appendix

Question 38

An additional location of lymphoid tissue

Answer 38

appendix

Question 39

All of these secondary organs are potential site for contact with foreign antigens which increase the probability of an immune response

Answer 39

Tonsils and Appendix

Question 40

The epidermis contains a number of intraepidermal lymphocytes. Most of these are T cells, which are uniquely positioned to combat any antigens that enter through the skin.

Answer 40

Cutaneous-Associated Lymphoid Tissue (CALT)

Question 41

Proteins that appear on cell surfaces can be used as markers to differentiate T cells and B cells. Proteins can also be used to distinguish the developmental stages of the two types of cells according to when these proteins appear

Answer 41

surface markers on lymphocyte

Question 42

A reference in standardizing names of membrane proteins found on all human white blood cells

Answer 42

CLUSTERS OF DIFFERENTIATION (CD)

Question 43

_____ has distinctive markers that include surface antigens CD19, CD45R, CD43, CD24, and c-Kit

Answer 43

Pro B-cells

Question 44

Synthesis of the heavy chain part of the antibody molecule occurs

Answer 44

Pre B-cells

Question 45

The first heavy chains synthesized are the _____, which belong to the class of immunoglobulins called ____, accompanied by an unusual light chain called a surrogate light chain

Answer 45

μ chains IgM

Question 46

Once the pre-B receptor (preBCR) is expressed, neighboring pre-B cells may send signals for further maturation

Answer 46

Pre B-cells

Question 47

Distinguished by the appearance of complete IgM molecules on the cell surface

Answer 47

immature B cells

Question 48

Completion of light chain rearrangement commits a cell to produce an antibody molecule with specificity for a particular antigen or group of related antigens. Variable regions, which occur on both the light and heavy chains, determine this specificity.

Answer 48

immature B-cells

Question 49

Other surface proteins that appear on the immature B cell include:

Answer 49

CD21 CD 40 Major histocompatibility complex (MHC) class II molecules

Question 50

Mature B-cells In the spleen, immature B cells develop into mature cells known _____, which remain in the spleen in order to respond quickly to any blood-borne pathogens they may come into contact with

Answer 50

marginal zone B cells

Question 51

Other immature B cells become _____, which are found in lymph nodes and other secondary organs

Answer 51

follicular B cells

Question 52

Both IgM and IgD are exhibited on their surface

Answer 52

mature B-cells

Question 53

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

Answer 53

Activated B-cells

Question 54

Identifying markers that include CD25, which is found on both activated T and B cells and acts as a receptor for interleukin-2 (IL-2), a growth factor produced by T cells. Additional receptors that appear at this time are specific for other growth factors produced by T cells. 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.

Answer 54

Activated B-cells Exhibit

Question 55

Spherical or ellipsoidal cells between 10 and 20 μm in size

Answer 55

plasma cells

Question 56

plasma cells are characterized by the presence of:

Answer 56

Abundant cytoplasmic immunoglobulin Little to no surface immunoglobulin

Question 57

plasma cells represents the most fully differentiated lymphocyte, and its main function:

Answer 57

antibody production

Question 58

Plasma cells are not normally found in the blood but are located in _____ in the peripheral lymphoid organs.

Answer 58

germinal centers

Question 59

nondividing, and after several days of antibody production, they die without further proliferation

Answer 59

plasma cells

Question 60

Also found in germinal centers and have a much longer life span than a resting B cell, represent progeny of antigen-stimulated B cells that are capable of responding to antigen with increased speed and intensity.

Answer 60

memory cells

Question 61

They are similar in appearance to unstimulated B cells, but they remain in an activated state for months or years, ready to respond to the initial antigen.

Answer 61

memory cells

Question 62

_____ of circulating lymphocytes in the peripheral blood are T cells, and these become differentiated in the thymus

Answer 62

60-80%

Question 63

Early surface markers on thymocytes (Lymphocyte precursors) that are committed to becoming T cells include ____

Answer 63

CD44 and CD25

Question 64

Orderly rearrangement of the genes coding for the antigen receptor, distinct surface markers appear during specific stages of development

Answer 64

T-cell differentiation

Question 65

Maturation is an elaborate process that takes place over a _____ as cells filter through the cortex to the medulla

Answer 65

3-week period

Question 66

Interaction with stromal cells under the influence of cytokines, especially _____, is critical for growth and differentiation

Answer 66

interleukin-7

Question 67

Lack CD4 and CD8 markers Rearrangement of the genes that code for the antigen receptor known as TCR begins at this stage Rearrangement of the β chain occurs

Answer 67

double-negative stage

Question 68

Thymocytes express both CD4 and CD8 antigens, they are called double-positive Double positive thymocytes proliferate and then begin to rearrange the genes coding for the alpha chain

Answer 68

double-positive stage

Question 69

Survivors of selection exhibit only one type of marker, either CD4 or CD8, and they migrate to the medulla

Answer 69

mature T cells

Question 70

CD4+ T cells recognize antigen along with _____

Answer 70

MHC class II protein

Question 71

while CD8+ T cells interact with antigen and ______

Answer 71

MHC class I proteins

Question 72

_____ bearing the CD4 receptor are termed helper, or inducer, cells, while the CD8-positive are cytotoxic T cells

Answer 72

T cells

Question 73

These mature T cells are released from the ____ and seed peripheral lymphoid organs. Resting T cells have a life span of up to several years in these peripheral organs

Answer 73

thymus

Question 74

Lymphocytes that do not express the markers of either T cells or B cells.

Answer 74

natural killer cells

Question 75

plays a critical role in NK cell development

Answer 75

interleukin-15

Question 76

Larger than T cells and B cells at approximately 15 μm in diameter

Answer 76

natural killer cells

Question 77

→ They contain kidney-shaped nuclei → Condensed chromatin and prominent nucleoli. → Have a higher cytoplasmic-nuclear ratio → Cytoplasm contains a number of azurophilic granules.

Answer 77

natural killer cells

Question 78

NK cells make up ____ of the circulating lymphoid pool and are found mainly in the spleen and peripheral blood

Answer 78

5-10%

Question 79

Have the ability to mediate cytolytic reactions and kill target cells without prior exposure to them.

Answer 79

NK cells

Question 80

They play an important role as a transitional cell bridging the innate and the acquired response to pathogens.

Answer 80

NK cells

Question 81

The fact that they lack specificity in their response is essential to their function as early defenders against pathogens

Answer 81

NK cells

Question 82

This gives time for the acquired response of specific T and B cells to be activated

Answer 82

NK cells

Question 83

allows NK cells to attach to and lyse any cells that are coated with antibody

Answer 83

CD16

Question 84

2 subsets of NK cells

Answer 84

A high level of CD56 and low or no CD16 Some CD56 and high levels of CD16

Question 85

produce more cytokines and help support antibody production

Answer 85

A high level of CD56 and low or no CD16

Question 86

have a higher cytotoxic activity

Answer 86

Some CD56 and high levels of CD16

Question 87

NK cell activity is stimulated by exposure to cytokines such as:

Answer 87

Interleukin-12 Interferon gamma Interferon beta

Question 88

Since these rises rapidly during a viral infection, NK cells are able to respond early on during an infection, and their activity peaks in about 3 days, well before antibody production or a cytotoxic T cell response

Answer 88

NK cells