Lymphoid Organs

Question 1

What are the primary lymphoid organs?

Answer 1

Bone marrow

Thymus

Question 2

What are the secondary lymphoid organs?

Answer 2

Lymph nodes

Spleen

Tonsils

Mucosa associated lymphoid tissue (MALT)

Question 3

What are the functions of the immune system?

Answer 3

Protection

Distinguis self from non-self

Remove infected, damaged or cancerous cells

Question 4

What is innate immunity?

Answer 4

Initial recognition and processing of antigens

Question 5

What is the adaptive immune system?

Answer 5

Immune response and effector function

Requires antigen presentation

Question 6

What is the humoral immunity?

Answer 6

Antibodies interacting with the antigen

Part of adaptive

Question 7

What is cell-mediated immunity?

Answer 7

Involves T-cells and antigen presenting cells

Question 8

What is clonal expansion?

Answer 8

B-cells proliferating into plasma cells that are specific to the antigen that the B-cell originally encountered

Question 9

What cells are a part of innate immunity?

Answer 9

Dendritic cells

Macrophages

Granulocytes, neurtophils, eosinophils, basophils

NK Cells

Question 10

What cells are a part of adaptive immunity?

Answer 10

Lymphocytes

B cells -humoral

T-cells - cell-mediated immunity

Plasma cells - produce antibodies

Question 11

What are neurtophils?

Answer 11

Innate immunity

Myeloid cells

Granules

Question 12

What are basophils?

Answer 12

Innate

Myeloid

Histamine releasing

Question 13

What are mast cells?

Answer 13

Innate

Myeloid

Tryptase/Histamine/Heparin

Allergy and Anaphylaxis

Question 14

What are Eosinophils?

Answer 14

Innate

Myeloid

Neoplasm, Allergy, Asthma, Collagen vascular disorders, Parasites (NAACP)

Question 15

What are Monocytes?

Answer 15

Innate Myeloid

Phagocytic, antigen presenting

Question 16

What are dendritic cells?

Answer 16

Antigen presenting cells

Question 17

What are Langerhans’ cells?

Answer 17

Located in the dermis

Question 18

What is a natural killer cell?

Answer 18

Lymphoid cell

Kill certain targets without sensitization, usually infected or damaged cells

Recognize self class 1 MHC molecules and kill cells lacking that self-antigen

Positive for CD16, CD56, and CD57

Question 19

What are plasma cells?

Answer 19

Main function is immunoglobulin synthesis

Lymphoid cell

Question 20

What is an antigen?

Answer 20

Molecules that bind to antibodies or the T-cell receptor

Bind small regions (epitopes) of large molecules

Linear or conformational

Question 21

What is the difference between a linear epitope or conformational epitope?

Answer 21

Linear binds in a sequence

Conformational is dependent on the 3D orientation of the antigen

Question 22

What are the antigen receptors on B lymphocytes?

Answer 22

Membrane bound antibodies

Recognize epitopes on a variety of extracellular molecules

Question 23

What are the antigen receptors on T lymphocytes?

Answer 23

T cell receptor

Recognize small peptides on the surface of APCs or Infected cell

Question 24

Describe the structure of an antibody?

Answer 24

Constant and variable regions

Heavy and light chains

The N-terminal domain of the heavy and light chains are highly variable

Question 25

What is the antigen binding domain composed of?

Answer 25

The variable regions of the light and heavy chains Highly specific 2 binding sites per antibody molecule

Question 26

What is IgM?

Answer 26

First antibody release Readily fixes and activates compliment

Question 27

What is IgA?

Answer 27

Mucosal immunity Prevents pathogen entry

Question 28

What is IgD?

Answer 28

Monomer attache tot he surface of B-cells, functions as B-cell receptor

Question 29

What is IgG?

Answer 29

80% of all antibodies in plasma Mainly from secondary and late primary responses Responsible for neonatal passive immunity

Question 30

What is IgE?

Answer 30

Monomer associated with allergy/parasites Causes mast cells to release histamine

Question 31

What is class-switching?

Answer 31

B-cells can antibody class switch but retain antigen specificity IgM at first, then IgG Important for infections stage determination

Question 32

Where are lymphocytes generated?

Answer 32

Bone marrow B-cells proliferate and mature here

Question 33

Where do T-cells mature?

Answer 33

The thymus

Question 34

What is the function of the thymus?

Answer 34

T-cell proliferation and maturation Negative self-selection of reactive clones Positive selection of MHC recognizing clones

Question 35

What are epithelial reticular cells?

Answer 35

Primary function is the deletion of auto-reactive T-cells Responsible for the education of the T-cells Have many antigens to expose T-cells to

Question 36

Describe the maturation of T-cells

Answer 36

Initially double negative for CD4 and CD8 Then double positive And eventually matures to only express either CD4 or CD8

Question 37

What are lymph nodes?

Answer 37

Monitor foreign antigens in tissues Adaptive immune responses to lymph borne antigens initiated

Question 38

What are high endothelial venules?

Answer 38

Allow passage of cells from the blood into the lymph nodes Important structure in lymph nodes not found in spleen

Question 39

What is the function of the germinal centers?

Answer 39

Seen in secondary lymphoid organs and spleen Mature B-cells proliferate, differentiate Class switching antibodies Located in the center of the follicle of lymph organs

Question 40

What is the phenotype of germinal center B-cells?

Answer 40

BCL-6 and CD10 postivie

Question 41

What is the spleen?

Answer 41

Largest organ in the lymphatic system Monitors foreign antigens in the blood Activates lymphocytes Removes aged RBCs

Question 42

What are periarteriolar lymphoid sheaths?

Answer 42

Portion of white pulp, populated by mostly T-cells and surround central arteries within the spleen

Question 43

What is Mucosa-associated lymphoid tissue?

Answer 43

Collections of lymphoid tissue within the lamina propria Associated with mucosal epithelium with openings to the external environment Large amounts of IgA are secreted by plasma cells