Body Defenses

Question 1

acquired immune responses

Answer 1

Responses that are selectively targeted against particular foreign material to which the body has previously been exposed; see also antibody-mediated immunity and cell-mediated immunity

Question 2

allergy

Answer 2

Acquisition of an inappropriate specific immune reactivity to a normally harmless environmental substance

Question 3

antibody-mediated immunity

Answer 3

A specific immune response accomplished by antibody production by B cells

Question 4

antigen

Answer 4

A large, complex molecule that triggers a specific immune response against itself when it gains entry into the body

Question 5

asthma

Answer 5

An obstructive pulmonary disease characterized by profound constriction of the smaller airways caused by allergy-induced spasm of the smooth muscle in the walls of these airways

Question 6

autoimmune disease

Answer 6

Disease characterized by erroneous production of antibodies against one of the bodyUs own tissues

Question 7

B lymphocytes (B cells)

Answer 7

White blood cells that produce antibodies against specific targets to which they have been exposed

Question 8

cell-mediated immunity

Answer 8

A specific immune response accomplished by activated T lymphocytes, which directly attack unwanted cells

Question 9

chemotaxin

Answer 9

A chemical released at an inflammatory site that attracts phagocytes to the area

Question 10

complement system

Answer 10

A collection of plasma proteins that are activated in cascade fashion on exposure to invading micro-organisms, ultimately producing a membrane attack complex that destroys the invaders

Question 11

cortisol

Answer 11

The adrenocortical hormone that plays an important role in carbohydrate, protein, and fat metabolism and helps the body resist stress

Question 12

cytokines

Answer 12

All chemicals other than antibodies that are secreted by lymphocytes

Question 13

cytotoxic T cells

Answer 13

The population of T cells that destroys host cells bearing foreign antigen, such as body cells invaded by viruses or cancer cells

Question 14

dendrites

Answer 14

Projections from the surface of a neuronUs cell body that carry signals toward the cell body

Question 15

dermis

Answer 15

The connective tissue layer that lies under the epidermis in the skin; contains the skinUs blood vessels and nerves

Question 16

endogenous pyrogen

Answer 16

A chemical released from macrophages during inflammation that acts by means of local prostaglandins to raise the set point of the hypothalamic thermostat to produce a fever

Question 17

epidermis

Answer 17

The outer layer of the skin, consisting of numerous layers of epithelial cells, with the outermost layers being dead and flattened

Question 18

fight-or-flight response

Answer 18

The changes in activity of the various organs innervated by the autonomic nervous system in response to sympathetic stimulation, which collectively prepare the body for strenuous physical activity in the face of an emergency or stressful situation, such as a physical threat from the outside environment

Question 19

helper T cells

Answer 19

The population of T cells that enhances the activity of other immune-response effector cells

Question 20

histamine

Answer 20

A chemical released from mast cells or basophils that brings about vasodilation and increased capillary permeability; important in allergic responses

Question 21

host cell

Answer 21

A body cell infected by a virus

Question 22

immune surveillance

Answer 22

Recognition and destruction of newly arisen cancer cells by the immune system

Question 23

immunity

Answer 23

The bodyUs ability to resist or eliminate potentially harmful foreign materials or abnormal cells

Question 24

immunoglobulin

Answer 24

Antibodies; gamma globulins

Question 25

inflammation

Answer 25

An innate, nonspecific series of highly interrelated events, especially involving neutrophils, macrophages, and local vascular changes, that are set into motion in response to foreign invasion or tissue damage

Question 26

innate immune responses

Answer 26

Inherent defense responses that nonselectively defend against foreign or abnormal material, even on initial exposure to it; see also inflammation, interferon, natural killer cells, and complement system

Question 27

interferon

Answer 27

A chemical released from virus-invaded cells that provides nonspecific resistance to viral infections by transiently interfering with replication of the same or unrelated viruses in other host cells

Question 28

interleukin 1

Answer 28

A multipurpose chemical mediator released from macrophages that enhances B cell activity

Question 29

interleukin 2

Answer 29

A chemical mediator secreted by helper T cells that augments the activity of all T cells

Question 30

keratin

Answer 30

The protein found in the intermediate filaments in skin cells that give the skin strength and help form a waterproof outer layer

Question 31

killer (K) cells

Answer 31

Cells that destroy a target cell that has been coated with antibodies by lysing its membrane

Question 32

leukocyte endogenous mediator (LEM)

Answer 32

A chemical mediator secreted by macrophages that is identical to endogenous pyrogen and exerts a wide array of effects associated with inflammation

Question 33

lymphoid tissues

Answer 33

Tissues that produce and store lymphocytes, such as lymph nodes and tonsils

Question 34

mast cells

Answer 34

Cells located within connective tissue that synthesize, store, and release histamine, as during allergic responses

Question 35

melanocyte-stimulating hormone (MSH)

Answer 35

A hormone produced by the anterior pituitary in humans and by the intermediate lobe of the pituitary in lower vertebrates; regulates skin coloration by controlling the dispersion of melanin granules in lower vertebrates; involved with control of food intake and possibly memory and learning in humans

Question 36

membrane attack complex

Answer 36

A collection of the five final activated components of the complement system that aggregate to form a porelike channel in the plasma membrane of an invading micro-organism, with the resultant leakage leading to destruction of the invader

Question 37

memory cells

Answer 37

B or T cells that are newly produced in response to a microbial invader but that do not participate in the current immune response against the invader: instead they remain dormant, ready to launch a swift, powerful attack should the same micro-organism invade again in the future

Question 38

natural killer cells

Answer 38

Naturally occurring, lymphocyte-like cells that nonspecifically destroy virus-infected cells and cancer cells by directly lysing their membranes on first exposure to them

Question 39

opsonin

Answer 39

Body-produced chemical that links bacteria to macrophages, thereby making the bacteria more susceptible to phagocytosis

Question 40

pathogens

Answer 40

Disease-causing micro-organisms, such as bacteria or viruses

Question 41

phagocytosis

Answer 41

A type of endocytosis in which large, multimolecular, solid particles are engulfed by a cell

Question 42

plasma cell

Answer 42

An antibody-producing derivative of an activated B lymphocyte

Question 43

self-antigens

Answer 43

Antigens that are characteristic of a personUs own cells

Question 44

T lymphocytes (T cells)

Answer 44

White blood cells that accomplish cellmediated immune responses against targets to which they have been previously exposed; see also cytotoxic T cells, helper T cells, and suppressor T cells

Question 45

thymus

Answer 45

A lymphoid gland located midline in the chest cavity that processes T lymphocytes and produces the hormone thymosin, which maintains the T cell lineage

Question 46

virulence

Answer 46

The disease-producing power of a pathogen