Anatomy and physiology chapter 20 the lymphatic system and immunity
What is perforin?
a protein produced by NK cells
All of the following are true of the thymus gland except that it
activates B cells
Cytotoxic T cells attack target cells by doing what?
activating genes that trigger apoptosis
Identify the structure labeled "3."
afferent lymphatic
The classic pathway of complement activation begins when the complement protein binds to
an antibody attached to an antigen
Nonspecific defenses would not include
antibodies
A substance that provokes an immune response is called a(n)
antigen
Compared to blood capillaries, lymph capillaries exhibit all of the following except that they
are smaller in diameter
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 thoracic duct originates from an expanded chamber called the
cisterna chyli
Each of the following is a physical barrier to infection except
complement
Lymphocytes that destroy foreign cells or virus- infected cells are ________ cells.
cytotoxic T
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
Characteristics of specific defenses include all of the following except
intrinsic
After puberty, the thymus gradually shrinks and becomes more fibrous, in a process called
involution
A sample of John's blood shows a high level of pyrogens. This would indicate that John
is running a fever
The white pulp of the spleen is populated by
lymphocytes
Class II MHC molecules are found only on which of the following?
lymphocytes and antigen-presenting cells
________ are connective tissues dominated by lymphocytes.
lymphoid tissues
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
The first line of cellular defense against pathogens are the
phagocytes
The role of antigen- presenting cells in immunity is to do all of the following except
phagocytosis
The cells responsible for producing antibody molecules are ________ cells.
plasma
In response to tissue damage and infection, circulating proteins called pyrogens
produce a fever
Lymph nodes do all of the following except
remove excess nutrients from the lymph
Lymphocytes
respond to antigens.
The thoracic duct drains lymph from all of the following regions except the
right breast
B cells prepare for activation by presenting an antigen bound to Class II MHC proteins in a process called
sensitization
The lobules of the thymus are divided by partitions called
septa
Defense of the body against a particular pathogen is provided by
specific immunity
The largest single collection of lymphoid tissue in the adult body is located in the
spleen
Leslie has a bad sore throat, and the lymph glands in her neck are swollen. This would indicate that
the affected lymph glands contain an increased number of lymphocytes
The merging of ________ forms the right lymphatic duct.
the right jugular, right subclavian, and right bronchomediastinal trunks
All of the following are true of lymphocytes except that
they are granulocytes.
Most of the lymph returns to the venous circulation by way of the
thoracic duct
The thymus produces several complementary hormones called
thymosins
Stem cells that will form T cells develop in the
thymus
T is to ________ as B is to ________.
thymus-dependent; bone marrow-derived
are large lymphoid nodules that are located in the walls of the pharynx.
tonsils
Identify the structures labeled "4."
trabeculae
The lymphatic system is composed of all of the following except
venae cavae
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.
Areas of the spleen that contain large aggregations of lymphocytes are known as
white pulp
The body's nonspecific defenses include all of the following except
B and T cells
Identify the dominant cell type in the area labeled "2."
B cells
T cells release cytokines to stimulate the activation of
B cells
The cells responsible for antibody- mediated immunity are the ________ cells.
B cells
B cells are primarily activated by the activities of
Helper T cells
Immunoglobulins that are primarily found in glandular secretions such as mucus, saliva, and tears are
IgA
Immunoglobulins that are found on the surface of B cells and may activate antibody production are
IgD
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 of the following statements regarding lymph is false?
Lacteals are prominent lymphatic vessels in the respiratory system.
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 patches
Regulatory T cells act to
Supress antigens
The cells directly responsible for cell- mediated immunity are the ________ cells.
T
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
The cell that dominates the deep cortical region of a lymph node is the ________ cell.
T helper
Which of these statements about lymph flow in a node is false?
The afferent lymphatics enters at the hilum.
Lymphocyte production does not occur in
The liver
Lymph draining from your right shoulder flows into
The right lymphatic duct
Lymphoid organs differ from lymphoid tissues in what way?
They are surrounded by a fibrous capsule and lymphoid tissues are not.
exists when the immune system does not respond to a particular antigen.
Tolerance
Identify the area where dividing lymphocytes are found.
WRONG 2 outer cortex
Before specific defenses are activated, most antigens must
WRONG either infect cells or be processed by a phagocyte.
The medullary sinus of a lymph node contains ________ lymphocytes and plasma cells
WRONG helper T
The attraction or repulsion of certain cells to chemicals in their environment is called
chemotaxis
Lymph nodes range in diameter from
1 mm to 25 mm
When an antigen is bound to a Class II MHC protein, it can activate a(n) ________ cell.
CD4 T
________ cells provide cell- mediated immunity.
CD8 T
Lymphatic vessels are located in almost all portions of the body except the
CNS
Which of the following concerning Class I MHC proteins is false?
bind complement
Examples of physical barriers against pathogens include all of the following except
blood
Lymphatic vessels commonly occur in association with
blood vessels
In passive immunity, the
body receives antibodies produced by other humans or by an animal.
Lymphocytes are produced and stored in all of the following except
brain
Inflammation produces all of the localized effects except
decreased blood flow
The primary function of the lymphatic system is
defending the body against both environmental hazards and internal threats.
Helper T cells do all of the following except
destroy target cells using perforins
The movement of phagocytes through the capillary wall is called
diapedesis
Identify the structure labeled "1."
efferent lymphatic
Fever is the maintenance of body temperature higher than
either 37.2°C or 99°F.
The lymphocytes are most important in
fighting infection
Which class of leukocytes is particularly abundant in the red pulp of the spleen?
free and fixed macrophages
Identify the region labeled "5."
germinal center
The various classes of immunoglobulins are differentiated on the basis of their
heavy-chain constant segments.
Cells that help regulate the antibody- mediated immune response are ________ cells.
helper T
Various types of macrophages are derived from
monocytes
Plasma contains ________ proteins that form the complement system.
more than 30
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
During a primary response to antigen exposure, 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 immunity