Biology Chapter 8: The Immune System (2 Stars)

Question 1

The immune system can be divided into ____ and adaptive immunity.

Answer 1

innate.

Question 2

Innate immunity is composed of defenses that are always active, but that cannot target a specific invader and cannot maintain immunologic memory; also called _________

Answer 2

nonspecific immunity.

Question 3

__________ is composed of defenses that take time to activate, but that target a specific invader and can maintain immunologic memory; also called specific immunity.

Answer 3

Adaptive immunity

Question 4

Immune cells come from the _______

Answer 4

bone marrow.

Question 5

The spleen and lymph nodes are sites where immune responses can be mounted, and in which ____ are activated.

Answer 5

B-cells

Question 6

The _____ is the site of T-cell maturation.

Answer 6

thymus

Question 7

Gut-associated lymphoid tissue (GALT) includes the tonsils and _____

Answer 7

adenoids.

Question 8

______ or white blood cells, are involved in immune defenses.

Answer 8

Leukocytes

Question 9

Many of the nonspecific defenses are ______

Answer 9

noncellular.

Question 10

The ____ acts as a physical barrier and secretes antimicrobial compounds, like defensins.

Answer 10

skin

Question 11

____ on mucous membranes traps pathogens; in the respiratory system, the mucus is propelled upward by cilia and can be swallowed or expelled.

Answer 11

Mucus

Question 12

Tears and saliva contain _____, an antibacterial compound.

Answer 12

lysozyme

Question 13

The stomach produces acid, killing most pathogens. Colonization of the gut helps prevent overgrowth by pathogenic bacteria through ______

Answer 13

competition.

Question 14

The complement system can punch holes in the cell walls of bacteria, making them osmotically _____

Answer 14

unstable.

Question 15

_____ are given off by virally infected cells and help prevent viral replication and dispersion to nearby cells.

Answer 15

Interferons

Question 16

Many of the nonspecific defenses are also ____

Answer 16

cellular.

Question 17

_____ ingest pathogens and present them on major histocompatibility complex (MHC) molecules. They also secrete cytokines.

Answer 17

Macrophages

Question 18

MHC class I (MHC-I) is present in all nucleated cells and displays _____ antigen (proteins from within the cell) to cytotoxic T-cells (CD8+ cells).

Answer 18

endogenous

Question 19

MHC class II (MHC-II) is present in professional antigen-presenting cells (macrophages, dendritic cells, some B-cells, and certain activated epithelial and displays exogenous antigen (proteins from outside the cell) to ______

Answer 19

helper T-cells (CD4+ cells).

Question 20

_____ cells are antigen-presenting cells in the skin.

Answer 20

Dendritic

Question 21

Natural killer cells attack cells not presenting ___ molecules, including virally infected cells and cancer cells.

Answer 21

MHC

Question 22

_____ include neutrophils, eosinophils, and basophils.

Answer 22

Granulocytes

Question 23

______ ingest bacteria, particularly opsonized bacteria (those marked with antibodies). They can follow bacteria using chemotaxis.

Answer 23

Neutrophils

Question 24

_____ are used in allergic reactions and invasive parasitic infections. They release histamine, causing an inflammatory response.

Answer 24

Eosinophils

Question 25

\_\_\_\_\_\_\_ are used in allergic reactions. Mast cells are related cells found in the skin.

Answer 25

Basophils

Question 26

Humoral immunity is centered on antibody production by plasma cells, which are activated \_\_\_\_\_

Answer 26

B-cells.

Question 27

Antibodies target a particular antigen. They contain two heavy chains and \_\_\_\_\_\_. They have a constant region and a variable region; the tip of the variable region is the antigen-binding region.

Answer 27

two light chains

Question 28

When activated, the antigen-binding region undergoes ______ to improve the specificity of the antibody produced. Cells may be given signals to switch isotypes of antibody (IgM, IgD, IgG, IgE, IgA).

Answer 28

hypermutation

Question 29

\_\_\_\_\_\_ antibodies can opsonize pathogens (mark them for destruction), cause agglutination (clumping) into insoluble complexes that are ingested by phagocytes, or neutralize pathogens.

Answer 29

Circulating

Question 30

Cell-surface antibodies can activate immune cells or mediate _____ reactions.

Answer 30

allergic

Question 31

\_\_\_\_\_\_ lie in wait for a second exposure to a pathogen and can then mount a more rapid and vigorous immune response (secondary response).

Answer 31

Memory B-cells

Question 32

Cell-mediated (cytotoxic) immunity is centered on the functions of \_\_\_\_\_

Answer 32

T-cells.

Question 33

T-cells undergo maturation in the ____ through positive selection (only selecting for T-cells that can react to antigen presented on MHC) and negative selection (causing apoptosis in self-reactive T-cells). The peptide hormone thymosin promotes T-cell development.

Answer 33

thymus

Question 34

Helper T-cells(Th or CD4+ ) respond to antigen on MHC-II and coordinate the rest of the immune system, secreting lymphokines to activate various arms of immune defense. Th1 cells secrete interferon gamma, which activates macrophages. Th2 cells activate \_\_\_\_\_, primarily in parasitic infections.

Answer 34

B-cells

Question 35

Cytotoxic T-cells (Tc, CTL, or CD8+ ) respond to antigen on ____ and kill virally infected cells.

Answer 35

MHC-I

Question 36

Suppressor (regulatory) T-cells (Treg) tone down the immune response ____ an infection and promote self-tolerance.

Answer 36

after

Question 37

\_\_\_\_\_\_ serve a similar function to memory B-cells.

Answer 37

Memory T-cells

Question 38

In autoimmune conditions, a ______ is recognized as foreign, and the immune system attacks normal cells.

Answer 38

self-antigen

Question 39

In allergic reactions, nonthreatening exposures \_\_\_\_\_an inflammatory response.

Answer 39

incite

Question 40

\_\_\_\_\_\_\_ is a method of inducing active immunity (activation of B-cells that produce antibodies to an antigen) prior to exposure to a particular pathogen.

Answer 40

Immunization

Question 41

\_\_\_\_\_ immunity is the transfer of antibodies to an individual.

Answer 41

Passive immunity

Question 42

The lymphatic system is a circulatory system that consists of one-way vessels with intermittent \_\_\_\_\_

Answer 42

lymph nodes.

Question 43

The lymphatic system connects to the cardiovascular system via the ____ in the posterior chest.

Answer 43

thoracic duct

Question 44

The lymphatic system equalizes ____ distribution, transports fats and fat-soluble compounds in chylomicrons, and provides sites for mounting immune responses

Answer 44

fluid