chapter 22: immune system

Question 1

what is the first step of inflammation?

Answer 1

immune cells and damaged cells of injured tissue release inflammatory and chemotactic factors

Question 2

in the second step of inflammation, the released chemicals cause _____________, including ________ of arterioles, increased _______ of capillaries, and stimulation of capillary endothelium to provide ___________

Answer 2

vascular changes; vasodilation; permeability; cell adhesion molecules (CAMs)

Question 3

what happens in the third step of inflammation?

Answer 3

leukocytes make their way to the site of inflammation through:
1. margination: leukocytes adhere to CAMs
2. diapedesis: leukocytes squeeze past the endothelial cells and migrate to the site of infection
3. chemotaxis: the process by which leukocytes migrate along the chemical gradient formed from chemicals released during the 1st step
4. delivery of plasma proteins: selective plasma proteins are brought to the site, including immunoglobulins, complement, clotting proteins, and kinins (similar to histamine)

Question 4

what 2 structures are a part of the 1st line of defense?

Answer 4

skin and mucous membranes

Question 5

the ____ and ________ of the skin provide a physical barrier, and _______ and _____ glands release ___________

Answer 5

dermis; epidermis; sweat; sebaceous; antimicrobials

Question 6

mucous membranes line ________ like the mouth, nose, anus, and vagina. they produce mucus that contains ___________ substances. they also have other mechanisms in other body areas (_______ in the respiratory tract)

Answer 6

body openings; antimicrobial; cilia

Question 7

how do phagocytes participate in innate immunity (2nd line of defense)?

Answer 7

• they engulf foreign substances (phagocytosis). this is done by neutrophils and macrophages
• dendritic cells present antigens to t-cells

Question 8

nk cells destroy unhealthy/unwanted cells by ________. they release cytotoxic chemicals called ______ which perforates the cell’s plasma membrane, and ___________ that enter through the membrane to destroy the cell

Answer 8

apoptosis; perforin; granzymes

Question 9

eosinophils _________ and release cytotoxic chemicals (________) to destroy _________cells

Answer 9

degranulate; perforins; parasitic

Question 10

_______ circulate in the blood and _________ reside in tissue. they both enhance __________. they also serve as __________ chemicals, attracting other immune cells as part of the inflammatory response

Answer 10

basophils; mast cells; inflammation; cytotoxic

Question 11

what do basophils and mast cells release?

Answer 11

histamine: increases vasodilation and capillary permeability
heparin: anticoagulant
eicosanoids: increase inflammation

Question 12

_________ are released by infected cells, alerting nearby cells to initate processes interfering with ________. these stimulate _______ to come destroy the infected cells though ________. NK cells also release interferons, stimulating ____________ to eliminate the shrivelled infected cells through ___________

Answer 12

interferons; replication; nk cells; apoptosis; macrophages; phagocytosis

Question 13

what are the 4 mechanisms of complement proteins?

Answer 13

1. opsonization: increases phagocytosis
2. inflammation
3. cytolysis: complement components kill pathogens
4. elimination: complement links Ag-Ab complexes to RBCs so they are transported to the liver and spleen

Question 14

what are the stages of a fever?

Answer 14

onset, stadium, defervescence

Question 15

the benefits of fever are increased rate of _____________, inhibits bacterial _____________, and increases __________ and __________ activity

Answer 15

tissue repair; replication; lymphocyte and interferon

Question 16

what are the 4 grades of fever?

Answer 16

low (38 - 38.8)
intermediate (38.8)
high (39.4 - 40)
dangerous high (>40)

Question 17

what are the 4 features of adaptive immunity?

Answer 17

specificity, uses lymphocytes, has memory, is systemic (circulates through blood and lymph)

Question 18

____ antibodies are the first type of antibody produced in response to an infection

Answer 18

IgM

Question 19

___ antibodies are found mainly in areas of the body such the nose, breathing passages, digestive tract, ears, eyes, and vagina

Answer 19

IgA

Question 20

___ antibodies are found as surface receptors on most B-lymphocytes

Answer 20

IgD

Question 21

___ antibodies are found in all body fluids and are the smallest but most abundant of the antibodies

Answer 21

IgG

Question 22

___ antibodies are bound to the surface of mast cells and basophils and are involved in allergies

Answer 22

IgE

Question 23

what is positive selection?

Answer 23

t cells learn to recognize and bind to MHC molecules

Question 24

what is negative selection?

Answer 24

t cells learn not to bind to self antigens (self tolerance)

Question 25

the final step of t-cell selection is the differentiation of t-cells into helper t-cells by the selective loss of ______, or cytotoxic t-cells by selective loss of _____

Answer 25

CD8; CD4

Question 26

_______ mediated immunity involves t-cells differentiating into killer and helper t-cells. helper t cells release ________, stimulating killer t cells and b cells, and regulating cells of innate immunity

Answer 26

cell; cytokines

Question 27

________ mediated immunity involved b-cells developing into _________ to synthesize and release antibodies

Answer 27

antibody; plasma cells

Question 28

3 functions of antibodies are due to AgAb binding. they are:

Answer 28

1. neutralization (covers antigenetic determinant)
2. agglutination (antibody crosslinks cells, forming a clump)
3. precipitation (form insoluble AgAb complex and drop out of [“precipitate out of”] body fluids)

Question 29

3 functions of antibodies are due to exposure of the Fc region. they are:

Answer 29

1. complement fixation (certain Ab classes bind to complement proteins)
2. opsonization (Fc region binds to phagocytic cells, triggering phagocytosis)
3. NK activation (Fc region binds to NK cells, triggering release of cytotoxic chemicals)

Question 30

what are 2 means of compliment activation?

Answer 30

1. classical pathway: compliment protein binds to an antibody previously attached to a foreign substance
2. alternative pathway: surface polysaccharides of bacterial and fungal cell walls bind with compliment protein