Chapter 8

Question 1

Innate Immunity

Answer 1

Defenses that are always active against pathogens but aren’t capable of targeting specific invaders

Question 2

Adaptive Immunity

Answer 2

Targets a specific pathogen and maintains immunologic memory of infection to mount a faster response during subsequent infections
* Takes loonger to mount a response

Question 3

B-Cells

Answer 3

• Develops in bone marrow
• Matures in bone marrow
• Activated in spleen/lymph nodes
• Produces antibodies
• Specific
• Humoral immunity

Question 4

T-Cells

Answer 4

• Develops in bone marrow
• Matures in thymus
• Coordinates immune system and directly kills infected cells
• Specific
• Cell-mediated
• Only specific defense against intracellular pathogens (viruses)

Four Types:
1. Cytotoxic T-cells
2. Helper T-cells
3. Memory T-cells
4. Suppressor T-cells

Question 5

Granulocytes

Answer 5

1. Neutrophils
2. Eosinophils
3. Basophils
4. Mast cells

Question 6

Agranulocytes

Answer 6

1. B- and T-cells (lymphocytes)
2. Monocytes (macrophages)

Question 7

Skin

Answer 7

• Physical barrier
• Secretes antimicrobial enzymes

Question 8

Defensins

Answer 8

Antibacterial enzymes on skin

Question 9

Lysozyme

Answer 9

• Antimicrobial
• Present in tears and saliva

Question 10

Mucus

Answer 10

• Present on mucous membraness
• Traps incoming pathogens
• In respiratory system, cilia propel mucus upward so it can be swallowed/expelled

Question 11

Stomach Acid

Answer 11

Antimicrobial mechanism in digestive system

Question 12

Normal Gastrointestinal Flora

Answer 12

Provides competition making it hard for pathogenic bacteria to grow in gut

Question 13

Complement

Answer 13

Set of proteins in blood that can create holes in bacteria

Question 14

Professional Antigen-Presenting Cells

Answer 14

1. Macrophages
2. Dendritic cells in skin
3. Some B-cells
4. Certain activated epithelial cells

Question 15

MHC-I

Answer 15

• Found in all nucleated cells
• Presents proteins created within the cell (endogenous antigens)
• Allows for detection of cells infected with intracellular pathogens (especially viruses)

Question 16

MHC-II

Answer 16

• Only found in antigen-presenting cells
• Presents poteins that result from digestion of extracellular pathogens that have been brought in by endocytosis (exogenous antigens)

Question 17

Natural Killer Cells

Answer 17

Activated by cells that don’t present MHC (ex: virally infected cells and cancer cells)

Question 18

Neutrophils

Answer 18

Activated by bacteria especially ones that have been opsonized (tagged with an antibody on their surface)

Question 19

Eosinophils

Answer 19

Activated by invasive parasites and allergens

Question 20

Basophils/Mast cells

Answer 20

Activated by allergens

Question 21

Plasma Cells

Answer 21

• Form from B-cells exposed to antigen
• Produce antibodies

Question 22

Memory B-Cells

Answer 22

• Form from B-cells exposed to antigen
• Wait for second exposure to given antigen to mount rapid strong response

Question 23

Helper T-Cells

Answer 23

• Coordinate immune system through lymphokines
• Respond to antigen bound to MHC-II

Question 24

Cytotoxic T-Cells

Answer 24

• Directly kill virally infected cells
• Respond to antigen bound to MHC-I

Question 25

Suppressor (Regulatory) T-Cells

Answer 25

* Quell immune response after pathogen has been cleared * Promote self-tolerance

Question 26

Memory T-Cells

Answer 26

Wait until second exposure to pathogen to mount rapid strong response

Question 27

Circulating Antibodies

Answer 27

Three Main Effects Can Have on Pathogen: 1. Can mark a pathogen for destruction by phagocytic cells **(opsonization)** 2. Cause agglutination of pathogen in insoluble complexes that can be taken up by phagocytic cells 3. Neutralize pathogen by preventing its ability to invade tissues

Question 28

Specific Antibodies

Answer 28

* B-cells mature in bone marrow and have some specificity * Antibodies can respond to a given antigen * Undergo hypermutation/rapid mutation of antigen-binding sites * B-cells that have highest affinity for antigen survive/proliferate increasing specificity for antigen over time

Question 29

Positive Selection

Answer 29

T-cells in thymus that can respond to antigen presented on MHC are allowed to survive * Those that don't respond undergo apoptosis

Question 30

Negative Selection

Answer 30

T-cells that respond to self-antigens undergo apoptosis before leaving thymus

Question 31

Active Immunity

Answer 31

Stimulation of immune system to produce antibodies against a pathogen * Weeks to build

Question 32

Passive Immunity

Answer 32

Transfer of antibodies to prevent infection without stimulation of plasma cells that produce these antibodies * Acquired immediately

Question 33

Thoracic Duct

Answer 33

Mainly responsible for returning materials from lymphatic circulation to cardiovascularsystem * lymphatic fluid into left subclavian vein

Question 34

Lymphatic System

Answer 34

* Collect excess interstitial fluid and return to circulatory system * Maintains balance of body nfluids * Accepts chylomicrons from small intestine and delivers to cardiovascular circulation * Absorbs fluid pushed into tissues *

Question 35

Clonal Selection

Answer 35

When adaptive immune system encounters antigen only cells with receptors (antibodies/T-cell receptors) specific to antigen are activated

Question 36

Phagocytes that Attack Bacteria

Answer 36

Neutrophils (found in blood, attack there or in tissues) Dendritic Cells (any material, in skin)