Lecture 2

Question 2

What percentage of total lymphocytes are circulating in the blood at any one time?

Answer 2

2%

Question 3

What do monocytes mature into in the tissues?

Answer 3

Macrophages or dendritic cells.

Question 4

Which MHC molecule do cytotoxic T cells recognize?

Answer 4

MHC1.

The CD8 molecule binds to MCH1.

Question 5

Is a blood lymphocyte count an accurate representation of total lymphocyes in the body?

Answer 5

No.

The majority of lymphocytes are found in the tissues.

Question 6

True or False: Basophils are covered in IgE antibody.

Answer 6

TRUE.

These cells are important in the detection of parasites.

Question 7

Identify the following cell types.

Answer 7

4. Monocyte
5. Endothelial cell
6. Neutrophil
7. Leukocyte

Question 8

True or False: NK cells are antigen-specific.

Answer 8

FALSE.

NK cells are part of the innate immune system.

Question 9

Where is the antigen binding site on an antibody?

Answer 9

On the light chain.

Question 10

True or false: leukocyte is synonymous with lymphocyte.

Answer 10

FALSE. Leukocyte refers to any white blood cell, whereas lymphocyte refers to T, B, and NK cells.

Question 11

Name the cells derived from the lymphoid cell lineage.

Answer 11

B cells, T cells, NK cells

Some dendritic cells

Question 12

What is the normal ratio of helper T cells (CD4+) to cytotoxic T cells (CD8+)?

Answer 12

2:1

If the ratio approaches 1:1, the patient becomes immunodeficient.

Question 13

Name the three lineages of hematopoeitic stem cells.

Answer 13

1. Erythroid
2. Myeloid
3. Lymphoid

Question 14

Where do dendritic cells mature?

Answer 14

In the tissues, where they act as important sentinel and antigen-presenting cells.

Question 15

What is the definition of “half life” for a blood cell?

Answer 15

The amount of time it takes for half of the cells of a particular type to be replaced in the blood stream.

Question 16

True or False: Each B cell can recognize multiple antigens.

Answer 16

FALSE

Each B cell expresses only one B cell receptor (BCR) and so can only recognize one antigen.

Question 17

Name the cells derived from the myeloid cell lineage.

Answer 17

Monocytes, eosinophils, basophils, neutrophils

Some dendritic cells

Mast cells

Question 18

What is a neutrophil’s primary function?

Answer 18

Protect against bacterial infection.

Question 19

What is the difference between cytotoxic T cell surface receptors and helper T cell surface receptors?

Answer 19

Helper T cells express CD4.

Cytotoxic T cells express CD8.

Question 20

Name the cells derived from the erythroid cell lineage.

Answer 20

RBCs and Platelets

Question 21

What is the term for an immature neutrophil released into the circulation?

Answer 21

Band cell

or

Band neutrophil

Question 22

List the secondary lymphoid tissues.

Answer 22

1. Lymph nodes.
2. Spleen.
3. MALT - mucosal-associated lymphoid tissue.

Question 23

Which leukocyte is present in the highest concentrations in the blood?

Answer 23

Neutrophil

Question 24

What is one of the first thing that happens when a lymphocyte encounters its target antigen?

Answer 24

Rapid clonal expansion (mitosis).

Question 25

True or false: You are going to kick some serious ass on the Immunology test.

Answer 25

GODDAM TRUE

Question 26

Define “addressins.”

Answer 26

Adhesion molecules on the surface of endothelial cells that allow leukocytes to identify where they are in the body.

Question 27

What is the difference between alpha beta T cells and gamma delta T cells?

Answer 27

Alpha beta T cells express CD4 and CD8.

Gamma delta T cells do not express CD4 or CD8.

Question 28

Which molecule is responsible for signal transduction after a T cell encounters an antigen?

Answer 28

CD3

Question 29

List the primary lymphoid tissues.

Answer 29

1. Thymus - maturation site of T cells.
2. Bursa of Fabricius - maturation site of B cells in birds.
3. Bone marrow - maturation site of B cells in primates, rabbits, and rodents.
4. Peyer’s patches - maturation site of B cells in ruminants, pigs, and dogs.

Question 30

List the types of lymphocytes.

Answer 30

1. T cells.
2. B cells.
3. Nk cells.

Question 31

Which MHC molecule do helper T cells recognize?

Answer 31

MCH2.

The CD4 molecule binds to MHC2.

Question 32

An animal showing an eosinophilia from blood work might have what kind of condition?

Answer 32

Parasitic infestation.

Question 33

Identify the leukocyte type.

Answer 33

Lymphocyte.

Question 34

What is meant by the term “memory cell?”

Answer 34

Long-lived clone of a lymphocyte.

Question 35

Identify the following blood cell types.

Answer 35

1. Erythrocyte
2. Basophil
3. Eosinophil

Question 36

True or False: B cells can recognize unprocessed antigens (i.e. not presented by the MHC).

Answer 36

TRUE

Question 37

Identify the components of this surface immunoglobulin.

Answer 37

1. Antigen binding site.
2. Light chain.
3. Heavy chain.
4. Trans-membrane region.

Question 38

True or false: Of all the WBCs, the bone marrow spends most of its energy making lymphocytes.

Answer 38

FALSE.

Most energy is spent on making neutrophils.

Question 39

How are new antigen receptors generated by T cells?

Answer 39

DNA rearrangement while maturing in the thymus.

If a newly generated receptor recognizes self antigens, the cells will quickly be destroyed.

Question 40

Lymphocytes make up what percentage of circulating white blood cells?

Answer 40

30%

Question 41

Name the leukocytes that are classified as granulocytes.

Answer 41

1. Neutrophils
2. Eosinophils
3. Basophils

Question 42

What are Peyer’s patches?

Answer 42

Part of the gut-associated lymphoid tissue (GALT).

Question 43

What is the half life of an eosinophil in the bood stream?

Answer 43

30 seconds.

Can live for 2 weeks in the tissues.

Question 44

What is meant by the term “neutropenia?”

Answer 44

A decreased number of neutrophils in the blood stream.