Nonspecific Defenses Of The Host

Question 1

Innate immunity vs adaptive immunity

Answer 1

Question 2

Innate immunity vs. adaptive immunity

Answer 2

Question 3

Susceptibility

Answer 3

lack of resistance to a disease

Question 4

Immunity

Answer 4

ability to ward off disease

Question 5

Innate immunity

Answer 5

defenses against any pathogen
Normal body functions

Question 6

Adaptive immunity:

Answer 6

immunity or resistance to a specific pathogen

Question 7

Physical/Mechanical Factors of innate immunity

Answer 7

Physical/Mechanical Factors of innate immunity
Skin
Epidermis consists of tightly packed cells with
Keratin, a protective protein

Question 8

Physical Factors
Mucous membranes

Answer 8

Mucus: traps microbes
Ciliary escalator: transports microbes trapped in mucus away from the lungs

Question 9

Physical Factors
Lacrimal apparatus:

Answer 9

Washes eye

Question 10

Saliva:

Answer 10

washes microbes off

Question 11

Urine:

Answer 11

Flows out

Question 12

Vaginal secretions:

Answer 12

Flows out

Question 13

Chemical Factors of innate immunity

Answer 13

Fungistatic fatty acid in sebum
Low pH (3–5) of skin
Lysozyme in perspiration, tears, saliva, and urine Low pH (1.2–3.0) of gastric juice
Low pH (3–5) of vaginal secretions

Question 14

Microbial antagonism/competitive exclusion:

Answer 14

normal microbiota compete with pathogens or alter the environment

Question 15

Commensal microbiota:

Answer 15

one organism (microbe)
benefits, and the other (host) is unharmed
May be opportunistic pathogens

Question 16

Host Toll-like receptors (TLRs) attach to

Answer 16

pathogen-associated molecular patterns (PAMPs)

Question 17

TLRs induce cytokines that..

Answer 17

regulate the intensity and duration of immune responses

Question 18

Second line of defense

Answer 18

Blood

Question 19

Answer 19

Question 20

Percentage of each type of white cell in a sample of 100 white blood cells

Answer 20

Neutrophils 60-70%
Basophils 0.5-1%
Eosinophils 2-4%
Monocytes 3-8%
Lymphocytes 20-25%

Question 21

Second line of defense

Answer 21

Lymphatic system

Question 22

Phagocytosis

Answer 22

Phago: from Greek, meaning eat
Cyte: from Greek, meaning cell
Ingestion of microbes or particles by a cell, performed by phagocytes

Question 23

Phagocytes

Answer 23

Neutrophils
Fixed macrophages Wandering macrophages Dendritic cells

Question 24

The phases of phagocytosis

Answer 24

Question 25

Microbial evasion of phagocytosis

Question 26

Inflammation

Answer 26

Activation of acute-phase proteins (complement, cytokine, and kinins) Vasodilation (histamine, kinins, prostaglandins, and leukotrienes) Redness Swelling (edema) Pain Heat

Question 27

Chemicals released by damaged cells

Answer 27

Question 28

Fever

Answer 28

Abnormally high body temperature Hypothalamus is normally set at 37°C Gram-negative endotoxins cause phagocytes to release interleukin-1 (IL-1) Hypothalamus releases prostaglandins that reset the hypothalamus to a high temperature Body increases rate of metabolism, and shivering occurs, which raise temperature Vasodilation and sweating: body temperature falls (crisis)

Question 29

Advantages of fever

Answer 29

Increases transferrins ● Increases IL-1 activity ● Produces interferon ● Many microbes can’t ● survive in the higher temperature

Question 30

Disadvantages of fever

Answer 30

Tachycardia (fast heart rate) Acidosis Dehydration 44–46°C fatal

Question 31

The complement system (immune response)

Answer 31

Serum proteins activated in a cascade (domino effect) Activated by Antigen–antibody reaction Proteins C3, B, D, P and a pathogen

Question 32

The Complement System

Answer 32

C3b causes opsonization C3a + C5a cause inflammation: inflammatory mediator C5b + C6 + C7 + C8 + C9 cause cell lysis (Mac attack) C:complement protein B:opsonization

Question 33

Effects of Complement Activation

Answer 33

Opsonization, or immune adherence: enhanced phagocytosis Membrane attack complex: cytolysis (MAC attack) Attract phagocytes Act as inflammatory mediators

Question 34

Classical pathway of a complement activation

Answer 34

Question 35

Alternative pathway of complement activation

Question 36

Lectin pathway of complement activation

Answer 36

Question 37

Some Bacteria Evade Complement

Answer 37

Capsules prevent C activation Surface lipid–carbohydrate complexes prevent formation of membrane attack complex (MAC) Enzymatic digestion of C5a

Question 38

Interferons (IFNs)

Answer 38

IFN- α and IFN- β: cause cells to produce antiviral proteins that inhibit viral replication

Question 39

IFN-y:

Answer 39

causes neutrophils and macrophages to phagocytize bacteria

Question 40

Innate Immunity Transferrins

Answer 40

Bind serum iron

Question 41

Innate Immunity Antimicrobial peptides

Answer 41

Lyse bacterial cells