CHAPTER 22- THE LYMPHATIC SYSTEM & IMMUNITY

The cells that perform immunological surveillance are the ________ cells.

NK

The cells responsible for the production of circulating immunoglobulins are ________ cells.

plasma

Place the following steps of NK cell killing in order.

*Recognition and adhesion *Realignment of Golgi apparatus *Secretion of perforin *Lysis of abnormal cell

An abnormal cell would be identified by the immune system because it showed

Class I MHC proteins with an antigen bound.

Immunoglobulins that attach to and sensitize mast cells and basophils are

IgE

Immunoglobulins, formed of five subunits, that are the first antibodies to be produced in response to infection, are

IgM

________ are fixed macrophages found in the liver.

Kupffer cells

Lymphatic organs differ from lymphatic tissues in what way?

They are surrounded by a fibrous capsule and lymphatic tissues are not.

All of the following are true of the thymus gland except that it

activates B cells

The body's innate defenses include all of the following except

antibodies

In order for a lymphocyte to respond to an antigen, the antigen must

bind to specific receptors on the lymphocyte surface.

When an antigen is bound to a Class II MHC protein, it can activate a ________ cell.

helper T

Lymph nodes do all of the following except

remove excess nutrients from the lymph

Each IgG has ________ binding sites for attachment to antigenic determinants.

2

The following are steps in the cell-mediated immune response. What is the correct sequence for these steps? 1. Several cycles of mitosis occur. 2. Antigen is engulfed and presented by a macrophage. 3. Cytotoxic T cells migrate to focus of infection. 4. T cells with specific receptors recognize the antigen. 5. T cells differentiate into cytotoxic T cells or T memory cells. 6. Cytotoxic T cells release perforin and/or lymphotoxin.

2, 4, 1, 5, 3, 6

The cells responsible for humoral immunity are the ________ cells.

B cells

Immunoglobulins that are found on the surface of B cells and that may activate antibody production are

IgD

Immunoglobulins that are most abundant and are responsible for resistance against many viruses, bacteria, and bacterial toxins are

IgG

Pregnant women are encouraged to get flu shots so that the maternal ________ can pass through the placenta to the fetus.

IgG

During the primary response, which antibody peaks sooner? During the secondary response, which antibody level is higher? (Figure 22-25)

IgM; IgG

The process by which antibodies bind to antigenic sites on viruses or toxins, rendering them incapable of binding to other cells, is called

Neutralization

Which of the following statements about lymph flow in a node is false?

The afferent lymphatic enters at the hilum.

Defense of the body against a particular pathogen is provided by

adaptive immunity

Lymphatic tissue is found in the greatest quantity in

adult spleen

Free phagocytes found in the air sacs of the lungs are called

alveolar macrophages

Class II MHC proteins are present in the plasma membrane only when

an antigen-presenting cell has engulfed and is processing an antigen.

The complement system works closely with and complements the action of

antibodies

A substance that provokes an immune response is called an

antigen

What type of immunity develops after receiving a vaccine? (Figure 22-17)

artificially acquired active immunity

Frank was bitten by a rattlesnake and received anti-venom containing neutralizing antibodies. Frank received ________ immunity and he ________ long-term immunity as a result.

artificially acquired passive immunity; will not have

In passive immunity, the

body receives antibodies produced by other humans or by an animal.

T cells develop from stem cells in the

bone marrow

The primary lymphoid tissues include

bone marrow and thymus

The attraction or repulsion of certain cells to chemicals in their environment is called

chemotaxis

Histamine increases blood flow and vascular permeability. This would account for all of the following changes that occur during inflammation except

chemotaxis of phagocytes.

Each of the following is a physical barrier to infection except

complement

A T cell can only become activated after being physically or chemically stimulated by the abnormal target cell in a process called

costimulation

Lymphocytes that destroy foreign cells or virus-infected cells are ________ cells.

cytotoxic T

When an antigen is bound to a Class I MHC molecule, it can stimulate a ________ cell.

cytotoxic T

The cells directly responsible for cellular immunity are the ________ cells.

cytotoxic T cells

The primary function of the lymphatic system is

defending the body against both external and internal threats.

The ________ lymphatics leave the lymph node at the hilum.

efferent

T cells and B cells can be activated only by

exposure to a specific antigen at a specific site in a plasma membrane

B cells are primarily activated by the activities of

helper T cells

The effects of activating the complement system include all of the following except

inhibition of the immune response.

Interferons

interfere with viral replication

Cytokines that make a cell and its neighbors resistant to virus infection are called

interferons

A sensitized B cell typically is not activated until

it binds a helper T cell that releases cytokines.

All of the following are true of the primary response of humoral immunity except that

it depends on memory B cells.

The lymphoid organ that acts like a filter as lymph passes through is

lymph nodes

Class II MHC molecules are found on which of the following?

lymphocytes and antigen-presenting cells

An inflammatory response is triggered when

mast cells release histamine and heparin

________ cells enable the immune system to respond quickly and robustly if the same antigen is encountered a second time.

memory

Fixed macrophages that are found in the central nervous system are called

microglia

The phagocytic antigen-presenting cells belong to the ________ group.

monocyte-macrophage

Various types of macrophages are derived from

monocytes

Sally has a tumor. In an effort to fight the cancerous cells her body increases the production of

natural killer cells (NK cells)

Immunity that results from exposure to an antigen in the environment is called ________ immunity.

naturally acquired active

Immunity that results from antibodies that pass through the placenta from mother to fetus is called ________ immunity.

naturally acquired passive

Specialized lymphatic capillaries called lacteals are

necessary for the transport of dietary lipids

During a primary humoral response to antigens all of the following occur except

neutrophils invade the surrounding areas, releasing chemotactic substances.

The process by which the surface of a microorganism is covered with antibodies and complement, rendering it more likely to be phagocytized, is called

opsonization.

In an experimental situation, a rabbit is exposed to a viral antigen to which it makes antibodies. These antibodies are then purified and injected into a human with the same viral disease. This is an example of

passive immunization

NK cells use ________ to lyse abnormal cells.

perforin

The first line of cellular defense against pathogens are the

phagocytes

The process by which soluble antigens combine with antibodies to form insoluble immune complexes is called

precipitation

Helper T cells do all of the following except

provide a rapid response to a future exposure to the antigen.

When antigens bind to inactive B cells and are brought into the cell by endocytosis to be displayed on the Class II MHC proteins this results in ________ of the B cells.

sensitization

Which is not a way that antigen-antibody complexes may cause elimination of the antigen?

sensitization

T cells and B cells destroy one antigen without affecting other antigens or normal tissues, this is termed

specificity.

In general, lymphocytes

spend most of their time in lymphoid tissue and have relatively long life spans.

Leslie has a severe sore throat and the lymph nodes in her neck are swollen. This would indicate that

the lymph nodes contain an increased number of lymphocytes.

The merging of ________ forms the right lymphatic duct.

the right jugular, right subclavian, and right bronchomediastinal trunks

Most of the lymph returns to the venous circulation by way of the

thoracic duct

Which of the following is not a secondary lymphoid tissue or organ?

thymus

________ are large lymphatic nodules that are located in the walls of the pharynx.

tonsils

The lymphatic system does all of the following except

transports gases to and away from lymph nodes. Submit

What feature do lymphatic vessels share with veins that allows lymph to flow in only one direction? (Figure 22-3)

valves

Lymphatic vessels begin in peripheral tissues and ultimately drain into

veins

All of the following are true of the secondary response of humoral immunity except that it

weakens quickly because memory B cells only survive for a year or two.

Areas of the spleen that contain large aggregations of lymphocytes are known as

white pulp