Immune Homework

Which statement regarding CD4 T cells is true?

Before they can initiate antibody-mediated immunity, inactive CD4 T cells must be exposed to appropriate antigens bound to Class II MHC proteins.

Inappropriate or excessive immune responses to antigens are

allergies.

Which type of specific defense is conferred by the administration of antibodies to combat infection?

artificially acquired passive immunity

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

cytotoxic

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

inhibition of the immune response.

Infection with the HIV virus occurs through

intimate contact with an infected person's body fluids

Antibodies may bind to superficial sites on bacteria or other toxins, making the toxin incapable of attaching itself to a cell. This mechanism is known as

neutralization.

Which of the following are abundant, mobile, and quick to phagocytize cellular debris or invading bacteria?

neutrophils

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 immunity.

The cells responsible for producing antibody molecules are ________ cells.

plasma

In response to tissue damage and infection, circulating proteins called pyrogens

produce a fever.

B cells prepare for activation by presenting an antigen bound to Class II MHC proteins in a process called

sensitization

The site on an antibody that is specifically tailored to fit a specific antigen is called the

variable segment.

Fever is the maintenance of body temperature higher than

37.2°C, or 99°F.

Characteristics of specific defenses include memory. specificity. versatility. tolerance. All of the answers are correct.

All of the answers are correct

In general, lymphocytes spend most of their time in lymphoid tissue. have relatively long life spans. have one nucleus. All of the answers are correct. None of the answers is correct.

All of the answers are correct

Inflammation produces localized pain. heat. redness. swelling. All of the answers are correct.

All of the answers are correct

Nonspecific defenses include interferons. phagocytic cells. physical barriers. inflammation. All of the answers are correct.

All of the answers are correct

The binding of an antigen to an antibody can result in agglutination or precipitation. neutralization of the antigen. complement activation and opsonization. All of the answers are correct. None of the answers is correct.

All of the answers are correct

________ will develop when the immune response mistakenly targets normal body cells and tissues.

Autoimmune disorders

Which lymphocytes are responsible for antibody-mediated immunity?

B cells

Lymphatic vessels commonly occur in association with

blood vessels

In passive immunity, the

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

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

chemotaxis of phagocytes.

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

chemotaxis.

Which is an expanded, saclike chamber that receives lymph from the inferior part of the abdomen, the pelvis, and the lower limbs?

cisterna chyli

Which lymph node structure is dominated by T cells?

deep cortex

The primary function of the lymphatic system is

defending the body against both environmental hazards and internal threats.

The movement of phagocytes through the capillary wall is called

diapedesis.

The lymphocytes are most important in

fighting infection

B cells are primarily activated by the activities of

helper T cells

Destruction of antigens or cell lysis can be caused by all of the following except

helper T cells

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

innate

Which of the following are secreted by T cells and NK cells, and stimulate macrophage activity?

interferon gamma

After puberty, the thymus gradually shrinks and becomes more fibrous, in a process called

involution.

Complement:

is a system of circulating proteins that assists antibodies in the destruction of pathogens.

A sample of John's blood shows a high level of pyrogens. This would indicate that John

is running a fever.

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

lymphocytes and antigen-presenting 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 the placenta from mother to fetus is called ________ immunity.

naturally acquired passive

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.

Which action of the complement system increases the degree of inflammation and accelerates blood flow to the region?

release of histamine

Defense of the body against a particular pathogen is provided by

specific immunity.

Which of the following is not a method in which antibodies work with features of innate immunity to destroy a pathogen?

stimulating interferon production

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

tears

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.

T is to ________ as B is to ________.

thymus-dependent; bone marrow-derived

A test to measure the antibody level a blood sample is called a(n)

titer.

Interferons are released by some macrophages and lymphocytes, but also by cells carrying what pathogen?

viruses

All of the following are true of the secondary response to antigen exposure except that it

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

Immunoglobulins that are primarily found in glandular secretions such as mucus, saliva, and tears are

IgA

Immunoglobulins that attach to and sensitize mast cells and basophils are

IgE

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

IgG

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

IgM

Which class of antibodies is secreted first after an antigen is encountered?

IgM

________ 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

________ are clusters of lymphoid nodules deep to the epithelial lining of the small intestine.

Peyer's patches

Choose the correct statement pertaining to allergies.

Sensitization to an allergen during the initial exposure leads to the production of large quantities of IgE.

Adaptive immunity is the result of the actions of

T and B cells

If the thymus shrank and stopped functioning properly, we would expect to see an immediate decrease in the number of

T cells

Which cells are responsible for cell-mediated immunity?

T cells

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

agglutination.

The classic pathway of complement activation begins when the complement protein binds to

an antibody attached to an antigen.

An allergen circulating in the bloodstream affects mast cells throughout the body, dropping blood pressure to dangerously low levels. This response is termed

anaphylactic shock

Memory Tc cells:

are produced by the thousands, but they do not differentiate further the first time the antigen triggers an immune response.

A substance that provokes an immune response is called a(n)

antigen.

Which of the following concerning Class I MHC proteins is false?

bind complement

Various types of macrophages are derived from

monocytes

________ cells provide cell-mediated immunity.

CD8 T

Lymphatic vessels are located in almost all portions of the body except the

CNS

In opsonization,

a pathogen is coated by proteins to facilitate its destruction by neutrophils and macrophages.

What is perforin?

a protein produced by NK cells

Cytotoxic T cells attack target cells by doing what?

activating genes that trigger apoptosis