Chapter 43: The Immune System

Question 0

Innate immunity

Answer 0

Defense that is active immediately upon infection and is the same whether or not the pathogen has been encountered previously; provides outer covering like skin/shell to provide a barrier to microbes; includes chemical barriers like mucous membranes

Question 1

Immune system

Answer 1

Defenses and responses to infection that enable animals to avoid or limit infections

Question 2

What a some basic components of innate immunity?

Answer 2

Skin/shell, chemical sections, linings of digestive tract, airway, exchange surfaces, etc.

Question 3

Molecular recognition

Answer 3

Receptor molecules bind specifically to molecules from foreign cells or viruses; enables self-detection

Question 4

Adaptive immunity

Answer 4

Defense found only in vertebrates: produce a vast arsenal of receptors for features previously encountered; aka acquired immune response

Question 5

True or false: adaptive immunity is activated after innate immunity and develops more slowly

Answer 5

True

Question 6

In what kinds of animals is innate immunity found?

Answer 6

All animals

Question 7

Chitin exoskeletons is a component of what in invertebrates?

Answer 7

Innate immunity

Question 8

What is another component of innate immunity, besides the exoskeleton, that protects invertebrate insects?

Answer 8

Lysozymes: break down bacterial cell walls

Question 9

Hemocytes

Answer 9

Immune cells that travel through the body in lymph, the insect circulatory fluid

Question 10

What are some functions of hemocytes in insects?

Answer 10

Phagocytosis, pathogen-killing chemical production, disruption of fungal/bacterial plasma membrane, production of antimicrobial peptides

Question 11

Antimicrobial peptides

Answer 11

Short chains of amino acids that circulate throughout insect bodies secreted by hemocytes and other cells, specific to different pathogens

Question 12

Immune cells of insects bind to molecules found only where?

Answer 12

In outer layers of fungi or bacteria

Question 13

Particular antimicrobial peptides act against what?

Answer 13

Different kinds of pathogens

Question 14

What are some barrier defenses in vertebrates?

Answer 14

Skin, mucous membranes lining digestive/respiratory/urinary/reproductive tracts, saliva, tears, mucous secretions

Question 15

Saliva, tears, and mucous secretions contain what?

Answer 15

Lysozymes that destroy bacteria

Question 16

What Isabel TLR?

Answer 16

Toll-like receptor: binds to mlcl fragments characteristic of a set of pathogens to detect fungal and bacterial components

Question 17

Neutrophils

Answer 17

Circulate in blood, attracted by signals from infected tissues, engulf and destroy infecting pathogens

Question 18

Macrophages

Answer 18

Larger phagocytic cells, can migrate or reside permanently

Question 19

Dendritic cells

Answer 19

Mainly populate tissues, also phagocytic, stimulate adaptive immunity

Question 20

Eosinophils

Answer 20

Often found beneath mucosal surfaces, low phagocytic activity, important to defend against multicellular invaders

Question 21

Natural killer cells

Answer 21

Circulate, release chemicals to lead to cell death

Question 22

Interferons

Answer 22

Proteins that provide innate defense by interfering with viral infections

Question 23

Complement system

Answer 23

~30 proteins in blood plasma, cause chemical reactions to lyse invaders

Question 24

Important inflammatory signaling molecule?

Answer 24

Histamine

Question 25

Where is histamine stored

Answer 25

Granules of mast cells, in connective tissue

Question 26

What does histamine do

Answer 26

Triggers blood vessels to dilate and become more permeable, allowing macrophages and neutrophils to discharge cytokines that enhance immune response

Question 27

Cytokines

Answer 27

Enhance immune response and promote blood flow to injury site and attract phagocytic cells

Question 28

Septic shock

Answer 28

Overwhelming systemic inflammatory response