chapter 20 and 21

Which of the following is NOT a component of the lymphatic system?

venae cavae

What is the primary function of the lymphatic system?

Defending the body against environmental hazards and internal threats.

In the lymphatic system, what are lymphocytes most important for?

fighting infection

Where are lymphocytes NOT produced and stored?

the brain

Compared to blood capillaries, how do lymph capillaries differ?

lymph capillaries are not smaller in diameter

Where are lymphatic vessels NOT located?

CNS

What do lymphatic vessels commonly occur in association with?

blood vessels

Which statement regarding lymph is false?

Lacteals are prominent lymphatic vessels in the respiratory system.

How does most of the lymph return to the venous circulation?

thoracic duct

What region does the thoracic duct NOT drain lymph from?

right breast

What merges to form the right lymphatic duct?

the right jugular, right subclavian, and right bronchomediastinal trunks

From what expanded chamber does the thoracic duct originate?

cisterna chyli

Lymph draining from your right shoulder flows into which duct?

the right lymphatic duct

Which of the following is NOT true of lymphocytes?

they are granulocytes

What response do lymphocytes have to antigens?

respond to antigens

Where does lymphocyte production NOT occur?

the liver

T is to thymus-dependent as B is to what?

bone marrow-derived

What is a substance that provokes an immune response called?

antigen

Which statement about lymph flow in a node is false?

The afferent lymphatic vessel enters at the hilum.

What are large lymphoid nodules located in the walls of the pharynx?

Tonsils

What are clusters of lymphoid nodules deep to the epithelial lining of the small intestine?

Peyer's patches

What do lymph nodes NOT do?

remove excess nutrients from the lymph

How do lymphoid organs differ from lymphoid tissues?

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

What does the medullary sinus of a lymph node contain?

B lymphocytes and plasma cells.

Which cell dominates the deep cortical region of a lymph node?

T helper cell

What is the range in diameter of lymph nodes?

1 mm to 25 mm

What type of tissues are dominated by lymphocytes?

Lymphoid tissues

What structure is labeled "1" in Figure 20-1?

Efferent lymphatic

What is the dominant cell type in the area labeled "2" in Figure 20-1?

B cells

What structure is labeled "3" in Figure 20-1?

Afferent lymphatic

What structures are labeled "4" in Figure 20-1?

Trabeculae

What region is labeled "5" in Figure 20-1?

Germinal center

Where are dividing lymphocytes found in Figure 20-1?

Area 5

What does it indicate when lymph glands in the neck are swollen during a sore throat?

the affected lymph glands contain an increased number of lymphocytes

Which of the following is NOT true of the thymus gland?

activates B cells

Where do stem cells that will form T cells develop?

bone marrow

If the thymus shrank and stopped functioning properly, what would immediately decrease in number?

T cells

What complementary hormones does the thymus produce?

thymosins

What is the process called when the thymus gradually shrinks and becomes more fibrous after puberty?

involution

What are the partitions that divide the lobules of the thymus called?

septa

What are the areas of the spleen that contain large aggregations of lymphocytes called?

white pulp

Where is the largest single collection of lymphoid tissue in the adult body located?

spleen

What populates the white pulp of the spleen?

lymphocytes

Which class of leukocytes is particularly abundant in the red pulp of the spleen?

free and fixed macrophages

Which of the following is NOT included in the body's nonspecific defenses?

B and T cells

Which of the following is NOT a nonspecific defense?

antibodies

Each of the following is a physical barrier to infection EXCEPT

complement

What are examples of physical barriers against pathogens?

epidermal layers

What is the first line of cellular defense against pathogens?

phagocytes

What are various types of macrophages derived from?

monocytes

What is the movement of phagocytes through the capillary wall called?

diapedesis

What is the attraction or repulsion of certain cells to chemicals in their environment called?

chemotaxis

Which cells perform immunological surveillance?

NK cells

What is perforin?

a protein produced by NK cells

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

viruses

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

inhibition of the immune response

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

an antibody attached to an antigen

How many proteins does plasma contain that form the complement system?

more than 30

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

opsonization

Inflammation produces all of the following localized effects EXCEPT

decreased blood flow

Fever is the maintenance of body temperature higher than

either 37.2°C or 99°F

An inflammatory response is triggered when

mast cells release histamine and heparin

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

produce a fever

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

chemotaxis of phagocytes

A sample of John's blood shows a high level of pyrogens. What would this indicate?

is running a fever

Characteristics of specific defenses include all of the following EXCEPT

intrinsic

Defense of the body against a particular pathogen is provided by

specific immunity

Immunity that is genetically determined and present at birth is called

innate

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

In passive immunity

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

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

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

Tolerance

The role of antigen-presenting cells in immunity is to do all of the following EXCEPT

phagocytosis

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

bind complement

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

lymphocytes and antigen-presenting cells

Before specific defenses are activated, most antigens must

bind to the DNA of the lymphocyte

The cells responsible for antibody-mediated immunity are the

B cells

Adaptive immunity is the result of the actions of

T and B cells

The cells directly responsible for cell-mediated immunity are the

T cells

Lymphocytes that destroy foreign cells or virus-infected cells are

cytotoxic T cells

Regulatory T cells act to

suppress antigens.

Cytotoxic T cells attack target cells by doing what?

activating genes that trigger apoptosis

__ cells provide cell-mediated immunity.

CD8 T

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

Memory

Helper T cells do all of the following except

destroy target cells using perforins

When an antigen is bound to a Class II MHC protein, it can activate a(n)

CD4 T

The cells responsible for producing antibody molecules are

plasma

Cells that help regulate the antibody-mediated immune response are

helper T

B cells are primarily activated by the activities of

helper T cells

T cells release cytokines to stimulate the activation of

B cells

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

sensitization

The various classes of immunoglobulins are differentiated on the basis of their

heavy-chain constant segments

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

IgG

Immunoglobulins that attach to and sensitize mast cells and basophils are

IgE

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

IgD

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

IgM

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

IgA

During a primary response to antigen exposure, all of the following occur except

neutrophils invade the surrounding areas, releasing chemotactic substances

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