Chapter 22 practice questions

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

costimuation

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

cytotoxic T

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

cytotoxic T

CD8 markers are to ________ T cells as CD4 markers are to ________ T cells.

cytoxic; helper

________ exists when the immune system does not respond to a particular antigen.

Tolerance

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

Tonsils

Immunoglobulins that attach to and sensitize mast cells and basophils are

IgE

Immunoglobins that are most abundant and are responsible for resistance against many viruses, bacteria, and bacterial toxins are ______.

IgG

Pregnant woman are encouraged to get flu shots so that maternal _______ can pass through the placenta to the fetus

IgG

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

Memory

The cells that perform immunological surveillance are the ________ cells.

NK

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

NK cells

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

inhibition of the immune response

Immunity that is genetically determined and present at birth is called ________ immunity.

innate

Interferons

interfere with viral replication

Hormones that regulate the activity of B cells and T cells and enhance nonspecific defense are called

interleukins

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

Which of the following is not a lymphocyte

macrophages

An inflammatory response is triggered when

mast cells release histamine and heparin

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

naturally acquired active

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

All of the following are characteristics of adaptive defenses except

present at birth

Helper T cells do all of the following except

provide a rapid response to a future exposure to the antigen

Stem cells that can form all types of lymphocytes are concentrated in the

red bone marrow

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

specificity

Lymph fluid enters the venous circulation via the

subclavian veins

A crime scene investigator found that a biological fluid sample contains a large amount of IgA-type antibody. This fluid is probably

tears

T lymphocytes are produced and stored in all of the following except

the brain

The lymphatic system is composed of all of the following except

the venae cavae

The lymphatic system does all of the following except

transports gases to and away from lymph nodes

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 to two

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

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

Class I MHC proteins with an antigen bound

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

activates B cells

The process by which antibodies bind to the antigen on the surface if cells, forming large immune complexes, is called

agglutination

Lymphatic capillaries are known for all of the following except

allowing nutrient gas exchange

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

antibodies

Newborns gain their immunity initially from

antibodies passed across the placenta from the mother

A substance that provokes an immune response is called an

antigen

The portions of an antigen to which antibodies bind are the

antigenic determinant sistes

Compared to blood capillaries, lymph capillaries exhibit all of the following except that they

are smaller in diameter

T cells and B cells can be activated only by

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

Dividing lymphocytes can be found in the ________ of the lymphoid nodule

germinal center

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

helper T

B cells are primarily activated by the activities of

helper T cells