CONCEPT REVIEW (Immunity)

Question 1

The ability to ward off disease is called immunity (resistance). Lack of resistance is called.

Answer 1

susceptibility

Question 2

Innate (nonspecific) immunity is always present to provide

Answer 2

rapid responses against disease.

Question 3

Adaptive (specific) immunity develops in response to

Answer 3

specific pathogens when they have

surpassed innate immunity defenses.

Question 4

The lymphatic system drains interstitial fluid, __________________, and protects against invasion.

Answer 4

transports dietary lipids

Question 5

What is the lymphatic system made up of?

Answer 5

The lymphatic system consists of lymph, lymphatic tissues, and red bone marrow.

Question 6

Lymphatic tissue is specialized reticular tissue containing large numbers of?

Answer 6

lymphocytes

Question 7

What does The lymphatic system

Answer 7

The lymphatic system drains excess interstitial fluid, transports lipids, and carries out immune responses against invasion.

Question 8

Lymph capillaries merge to form larger vessels, called lymphatic vessels, which convey lymph into and out of ___________________.

Answer 8

lymph nodes.

Question 9

The route of lymph flow is from lymph capillaries to lymphatic vessels, to lymph _________, then to the thoracic duct and right lymphatic duct.

Answer 9

trunks

Question 10

What are the lymphatic organs?

Answer 10

The lymphatic organs and tissues include the thymus, lymph nodes, spleen, and lymphatic follicles.

Question 11

What are the primary lymphatic organs? What happens there?

Answer 11

Primary lymphatic organs and tissues are the sites where stem cells divide and develop into immunocompetent B cells and T cells. They are the red bone marrow and the thymus.

Question 12

What are the secondary organs and tissues? What happens there?

Answer 12

Secondary lymphatic organs and tissues are the sites where most immune responses occur. They include lymph nodes, the spleen, and lymphatic follicles.

Question 13

The thymus lies _____________ to the sternum and ____________ to the heart. It is the site of T cell maturation.

Answer 13

posterior

superior

Question 14

Lymph nodes are located along ____________. Lymph enters lymph nodes through __________lymphatic vessels, is filtered, and exits through __________ lymphatic vessels.

Answer 14

lymphatic vessels

afferent

efferent

Question 15

What is the largest mass of lymphatic tissue in the body?

Answer 15

The spleen is the largest mass of lymphatic tissue in the body

Question 16

What does the spleen do?

Answer 16

It is a site where B cells divide into plasma cells and macrophages phagocytize worn­out red blood cells and platelets

Question 17

What are Lymphatic follicles?

Answer 17

Lymphatic follicles are concentrations of lymphatic tissue that are not surrounded by a capsule

Question 18

Where are Lymphatic follicles found?

Answer 18

They are scattered throughout the mucosa of the gastrointestinal, respiratory, urinary, and reproductive tracts and are termed mucosa­associated lymphatic tissue (MALT). Tonsils are examples of lymphatic follicles

Question 19

Innate (nonspecific) immunity includes physical factors, chemical factors, _______________, phagocytes, inflammation, fever, and antimicrobial proteins.

Answer 19

natural killer cells

Question 20

The ______________ membranes are the first line of defense against entry of pathogens. The closely packed keratinized cells of the epidermis are a physical barrier to invasion. Mucous membranes have mucus that traps microbes and cilia that sweep microbes away from the lungs. Tears, ___________, urine, and vaginal secretions flush microbes from the body. Defecation and ________ expel microbes. The ___________ of gastric juice and vaginal secretions discourages bacterial growth.

Answer 20

skin and mucous

saliva

vomiting

acidity

Question 21

Pathogens that get past the first line of defense are attacked by internal defenses, they are?

Answer 21

Natural killer cells and phagocytes attack and kill pathogens and defective cells in the body.

Question 22

Inflammation aids disposal of microbes, toxins, or foreign material at the site of an injury and prepares the site for ___________________.

Answer 22

tissue repair

Question 23

How does fever help the immune response?

Answer 23

Fever intensifies the antiviral effects of interferons,

inhibits growth of some microbes,

and speeds up body reactions that aid repair.

Question 24

Antimicrobial proteins (_______________ and complement) inhibit microbial growth.

Answer 24

Interferons

Question 25

What does the complement system do?

Answer 25

The complement system destroys microbes through phagocytosis, cytolysis, and inflammation.

Question 26

The complement system is a group of proteins that “complement” immune responses and help clear _______________ from the body. Once activated, complement proteins bring about phagocytosis, _____________, and inflammation.

Answer 26

antigens

cytolysis

Question 27

What is adaptive immunity?

Answer 27

Adaptive immunity involves the production of a specific lymphocyte or antibody against a specific antigen.

Question 28

What are antigens?

Answer 28

Antigens are foreign substances that produce an immune response. Adaptive immunity has specificity for particular antigens and memory of previous antigens.

Question 29

Where do B cells and T cells arise from?

Answer 29

B cells and T cells arise from stem cells in red bone marrow. B cells mature in red bone marrow; T cells mature in the thymus.

Question 30

How do B & T cells help build immunity and strength to fight?

Answer 30

B cells and T cells become immunocompetent, capable of carrying out adaptive immune responses by inserting antigen receptors into their plasma membranes. Antigen receptors are molecules that are capable of recognizing specific antigens.

Question 31

In _______________ immunity, cytotoxic T cells directly attack invading antigens and are effective against intracellular pathogens, cancer cells, and transplanted tissues. In ____________y­ mediated immunity, B cells become plasma cells that secrete antibodies used against extracellular pathogens.

Answer 31

cell­ - mediated

anti -body

Question 32

What is Clonal selection ?

Answer 32

Clonal selection is the process by which a lymphocyte divides and differentiates into a clone of cells that can recognize the same specific antigen as the original lymphocyte.

Question 33

What cells are produced in Clonal selection?

Answer 33

The clone includes effector cells and memory cells. Effector cells destroy or inactivate the antigen.

Memory cells do not actively participate in the initial immune response, but if the antigen reappears in the body in the future, memory cells quickly divide and differentiate into more effector and memory cells.

Question 34

What are Self -­antigens?

Answer 34

called major histocompatibility complex (MHC) molecules are unique to each person’s body cells. All cells except red blood cells display MHC molecules.

Question 35

Antigen­ presenting cells process ____________ antigens (present outside body cells), which results in an antigen–MHC complex being displayed on the cell’s plasma membrane. The exogenous antigen–MHC complexes trigger adaptive immune responses in T cells.

Answer 35

exogenous

Question 36

________________ antigens (present inside body cells) bind with MHC molecules. The endogenous antigen–MHC complexes insert in the plasma membrane, which signals that the cell is infected.

Answer 36

Endogenous

Question 37

What are Cytokines ?

Answer 37

Cytokines are small hormones that stimulate or inhibit many normal cell functions such as growth and differentiation. Other cytokines regulate immune responses.

Question 38

A cell­ - mediated immune response begins with activation of a small number of_______________ by a specific antigen and ultimately results in elimination of the intruder.

Answer 38

T cells

Question 39

During the activation process, T cell receptors recognize and bind to antigen fragments associated with ____________molecules on the surface of a body cell. Activation of T cells also requires ____________, usually by interleukin­2. Once a T cell has been activated, it undergoes clonal selection

Answer 39

MHC

costimulation

Question 40

Helper T cells display the ____________ and are activated by MHC molecules presented by an
APC. Once activated, helper T cells undergo clonal selection, then secrete several cytokines, most importantly ______________, which acts as a costimulator for other T cells, B cells, and natural killer cells.

Answer 40

CD4 protein

interleukin­2

Question 41

Cytotoxic T cells display the __________ and are activated by MHC molecules on the surfaces of body cells infected by microbes, ___________, and transplanted tissue cells. Once activated, cytotoxic T cells undergo clonal selection.

Answer 41

CD8 protein

tumor cells

Question 42

Active cytotoxic T cells kill infected cells by releasing ______________, which cause target cell apoptosis (phagocytes then kill the released microbes); perforin, which causes target cell cytolysis; and granulysin, which enters the target cell to destroy microbes.

Answer 42

granzymes

Question 43

Antibodies form antigen–antibody complexes with their complementary antigens, which disables antigens by blocking attachment of the antigen to body cells, _______________, agglutinating and precipitating antigen, activating complement, and enhancing _______________

Answer 43

immobilizing bacteria

phagocytosis

Question 44

How does Immunological memory help the body respond?

Answer 44

Immunological memory results in a more intense secondary response to an antigen.