7.2 HOST-MICROORGANISM INTERACTIONS - HOST RESISTANCE

Question 1

HOST RESISTANCE

Answer 1

Physical Barriers
Macrophages

Question 2

Physical Barriers

Answer 2

a. Healthy, Intact Skin
b. Cleansing Mechanisms
c. Antimicrobial Substances
d. Indigenous Microbial Flora
e. Phagocytosis

Question 3

→ primary mechanical barrier to infection

Answer 3

Healthy, Intact Skin

Question 4

→has substantial numbers of microbial flora that contribute to a low pH, compete for nutrients, and produce bactericidal substances addition

Answer 4

Healthy, Intact Skin

Question 5

→ ensures that relatively few organisms can survive and prosper in the acid environment

Answer 5

low pH resulting from long-chain fatty acids secreted by sebaceous glands

Question 6

Spp capable of penetrating normal, healthy skin

Answer 6

Leptospira spp., Francisella tularensis, Treponema spp

Question 7

Mechanism of urethral opening as a barrier

Answer 7

Stricture

Question 8

This action allows the urethra to be less susceptible to microorganism growth

Answer 8

urination

Question 9

Found in the cervical opening that acts as a barrier for microorganism

Answer 9

thick mucus plug

Question 10

What natural process involves the shedding of the skin surface to remove potential pathogens?

Answer 10

Desquamation

Question 11

What two antimicrobial components are found in tears?

Answer 11

IgA and lysozyme

Question 12

How does the respiratory tract help remove trapped microbes?

Answer 12

Mucus traps particles and sweeps them to the oropharynx.

Question 13

What type of epithelium lines the trachea and aids in clearing particles upward?

Answer 13

Ciliated epithelium

Question 14

Which reflex helps expel potentially infected agents from the respiratory system?

Answer 14

Cough-sneeze reflex

Question 15

What two mechanisms in the gastrointestinal tract prevent organisms from attaching to the intestinal epithelium?

Answer 15

Mucous secretions and peristalsis

Question 16

What cleansing action in the genitourinary tract helps prevent infection?

Answer 16

Voiding urine

Question 17

What characteristic of the vagina inhibits colonization by transient organisms?

Answer 17

Acidity

Question 18

Cleansing Mechanisms of the body

Answer 18

Desquamation
IgA and lysozyme in tears
Mucus in RT
Ciliated epithelium in trachea
Cough-sneeze reflex
Mucous secretions and peristalsis of the GI tract

Voiding urine
Acidity of vagina

Question 19

Antimicrobial Substances

Answer 19

Lysozyme
Secretory IgA
β-lysins
Interferon

Question 20

→low-molecular-weight (approximately 20,000 D) enzyme that hydrolyzes the peptidoglycan layer of bacterial cell walls

Answer 20

Lysozyme

Question 21

Lysozyme found in

Answer 21

serum,
tissue fluids,
tears,
breast milk,
saliva, and
sweat

Question 22

→serve as opsonins, fix complement and neutralize the infecting
organism

Answer 22

Secretory IgA

Question 23

Secretory IgA →found in

Answer 23

mucous secretions of the

respiratory,
genital, and
digestive tracts

Question 24

Secretory IgA serve as

Answer 24

opsonins

Question 25

→low-molecular-weight cationic proteins in serum →lethal against gram-positive bacteria and are released from platelets during coagulation

Answer 25

β-lysins

Question 26

→inhibits proliferation of viruses

Answer 26

Interferon

Question 27

→compete with pathogens for nutrients and space

Answer 27

Indigenous Microbial Flora

Question 28

→substances that inhibit the growth of closely related bacteria

Answer 28

Bacteriocins

Question 29

→process by which phagocytes engulf and dispose of microorganisms and cell debris

Answer 29

Phagocytosis

Question 30

necessary for the killing and digestion of the engulfed particles

Answer 30

Lysosomes

Question 31

Lysosomes [enumerate]

Answer 31

myeloperoxidase, proteases, cathepsin, lactoferrin, lysozyme, and elastase

Question 32

→has receptors on the cell membrane for some complement components that stimulate cell motion, the metabolic burst, and secretion of the lysosome contents into a phagosome

Answer 32

PMN - polymorphonuclear leukocyte

Question 33

PMN circulating half life hours

Answer 33

2-7

Question 34

PMN may migrate to the tissues where their half life is

Answer 34

less than a week

Question 35

→circulate as monocytes for 1 to 2 days and then migrate through the blood vessel walls into the tissues and reside in specific tissues as part of the MONONUCLEAR PHAGOCYTE SYSTEM

Answer 35

Macrophages

Question 36

Macrophages are part of the [system]

Answer 36

MONONUCLEAR PHAGOCYTE SYSTEM

Question 37

→widely distributed in the body and play a central role in specific immunity and nonspecific phagocytosis

Answer 37

Macrophages

Question 38

Chemotaxis two types

Answer 38

Diapedesis Chemotaxis

Question 39

→ movement of the neutrophils between the endothelial cells of the blood vessels into the tissues

Answer 39

DIAPEDESIS

Question 40

→directed migration of PMNs into the area of infection

Answer 40

CHEMOTAXIS

Question 41

→facilitated by the binding of specific antibodies to the microorganism

Answer 41

Attachment

Question 42

→coating of the bacterium with antibody or complement components results in enhanced phagocytosis by the PMN

Answer 42

OPSONIZATION

Question 43

Neutrophils have membrane receptors for?

Answer 43

Fc region of IgG1 IgG3 C3b component of complement

Question 44

Which antibody classes can bind to organisms to initiate opsonization?

Answer 44

IgG1 or IgG3

Question 45

What happens when the antibody response is insufficient for opsonization?

Answer 45

Complement is fixed on the surface of the organism

Question 46

Which pathway can be activated by endotoxins or polysaccharides for opsonization?

Answer 46

Alternative complement pathway

Question 47

✓Cell membrane of the phagocytic cell invaginates and surrounds the attached particle

Answer 47

Ingestion

Question 48

In Ingestion ✓Particle is taken into the cytoplasm and enclosed within a vacuole called a

Answer 48

PHAGOSOME

Question 49

✓Phagosome fuses with lysosomes

Answer 49

PHAGOLYSOSOME

Question 50

Lysosomes release their contents into the phagosome

Answer 50

DEGRANULATION

Question 51

Ingestion included enzymes

Answer 51

proteases, lipases, RNase, DNase, peroxidase, and acid phosphatase

Question 52

→phagocytosis of a particle triggers a significant increase in the metabolic activity of the neutrophil or macrophage

Answer 52

Metabolic or Respiratory Burst

Question 53

Killing / Metabolic or Respiratory Burst increases in

Answer 53

glycolysis

Question 54

→body’s response to injury or foreign body

Answer 54

Inflammation

Question 55

→hallmark of inflammation:

Answer 55

accumulation of large numbers of phagocytic cells

Question 56

→leukocytes release mediators or cause other cell types to release which cause ______________ as a result of greater blood flow, edema from an increase in vascular permeability, and continued phagocyte accumulation, resulting in ____________

Answer 56

erythema pus

Question 57

CARDINAL SIGNS OF INFLAMMATION

Answer 57

SWELLING, tumor REDNESS, rubor HEAT, calor PAIN, dolor LOS OF FUNCTION

Question 58

Chemical Mediatiors of Inflammation:

Answer 58

✓Histamine ✓Kinins ✓Leukotrienes ✓Prostaglandins ✓Acute phase reactants ✓Cytokines

Question 59

✓Acute phase reactants examples

Answer 59

CRP, Serum amyloid A, antitrypsin, fibrinogen

Question 60

✓Cytokines that mediate inflammation

Answer 60

IL-1, IL-6, TNF-α, IFN-γ, IL-2