Defense of the Respiratory System and Response to Injury

Question 1

what makes the lungs a vulnerable site for pathogen entry into the tissues?

Answer 1

minimal thickness of air/blood barrier

Question 2

what is the common pulmonary response to antigens?

Answer 2

non-inflammatory Th2-mediated

Question 3

what is pneumonia?

Answer 3

an overgrowth of pathogenic species and loss of normal microbiome organisms followed by host inflammation

Question 4

what are the major host defenses?

Answer 4

upper respiratory expulsions
mucociliary escalator
neutrophils and macrophages
soluble mucus contents
inflammatory cells
immune response

Question 5

what microorganism factors can affect the outcome of infectious agents entering the respiratory system?

Answer 5

number of organisms
pathogen virulence
whether or not they are “host adapted”

Question 6

what does it mean for something to be “host-adapted”?

Answer 6

microorganism has evolved mechanisms to infect only one or a few species

Question 7

what are the humoral defenses in the lungs against microorganisms?

Answer 7

plasma proteins with antibodies
complement proteins
C-reactive protein
surfactant proteins A and D
pentraxin-3

Question 8

the mucus blanket functions as a _______________, _______________, _________________ barrier in the airways

Answer 8

mechanical
chemical
biological

Question 9

what can decrease mucociliary function?

Answer 9

dehydration thickens fluid
atropine
physical airway injury
chemical injury
bacterial attachment to airway cells
viral infection
inflammatory mediators
allergen challenge

Question 10

what species have intravascular macrophages in small pulmonary capillaries?

Answer 10

horses
ruminants
swine

Question 11

why does loss of goblet or club cells result in impaired defense mechanism?

Answer 11

airway mucus has factors that can directly injure pathogens, block attachment of bacteria to mucosal surfaces, opsonize bacteria/viruses/fungi

Question 12

phagocytosis of bacteria by alveolar macrophages results in _____________________

Answer 12

recruitment of neutrophils (chemotactic mediators and diapedesis of neutrophils)

Question 13

true/false: it is normal to find neutrophils in a TTA or BAL sample

Answer 13

false: if present indicates inflammation and often infection

Question 14

what does the specific immune response involve?

Answer 14

dendritic cells sampling antigens and migrating through lymph to present to antigen-specific T cells

Question 15

what cells are involved in the innate immune response?

Answer 15

macrophages
dendritic cells
neutrophils

Question 16

where does bronchus-associated lymphoid tissue develop?

Answer 16

after birth at sites of particle deposition- airway bifurcations

Question 17

what cells overlay BALT?

Answer 17

M cells

Question 18

what synthesizes IgA and why?

Answer 18

committed plasma cells in BALT and submucosa
after stimulation by receptor-mediated uptake and transport through epithelial cells

Question 19

what is IgA important in?

Answer 19

virus and toxin neutralization, prevention of bacterial and viral attachment to epithelial surfaces, bacterial entrapment/agglutination

Question 20

where is IgG primarily found in the respiratory tract?

Answer 20

alveolar lining fluid

Question 21

what does IgG do in the respiratory tract?

Answer 21

opsonization of bacteria to enhance phagocytosis
complement fixation
antibody-dependent cytotoxicity

Question 22

where do IgA and IgG predominate in the respiratory tract?

Answer 22

IgA in upper
IgG in lower

Question 23

what do epitheliotropic viruses do?

Answer 23

infect and injure airway or alveolar epithelial cells: loss of integrity of the epithelial barrier and exposure deeper tissues

Question 24

how can viruses alter the mucociliary excalator?

Answer 24

attach to cilia
alter mucous layer composition

Question 25

how can viruses impact macrophages?

Answer 25

apoptosis or suppress their phagocytic and bactericidal function infect: cytotoxic activity directed against

Question 26

what are two pathogenic microorganisms that target the respiratory epithelium by binding between sialic acid-containing receptors on the ciliary membrane and surface adhesion proteins on the pathogen?

Answer 26

Mycoplasma and Bordatella spp

Question 27

how long does it take after mechanical trauma for healing to take place?

Answer 27

14 days for epithelium replaced 28 days for full function

Question 28

what does chronic injury of the epithelium and then continued injury lead to?

Answer 28

goblet cell hyperplasia squamous metaplasia

Question 29

when does acute bronchitis take place?

Answer 29

following irritation or airway infection with viruses parasitic bronchitis is important in ruminants

Question 30

what is purulent bronchitis characterized by?

Answer 30

neutrophil-rich exudate in airway lumen

Question 31

what is chronic bronchitis morphologically?

Answer 31

hyperplasia and hypertrophy of goblet cells and mucous glands with increased mucous production

Question 32

what is bronchiolitis obliterans?

Answer 32

bronchial lumen is obliterated by proliferation of connective tissue and epithelium- dogs

Question 33

what can happen in swine, sheep, cattle, or rodents with chronic mycoplasma infection?

Answer 33

obstruction due to hyperplasia of the bronchus associated lymphoid tissue

Question 34

what is bronchiestasis?

Answer 34

sequela of long-term airway infection and inflammation

Question 35

what are two ways injurious agents can reach the lungs? what results?

Answer 35

airways or circulation aerogenous or hematogenous pneumonia

Question 36

what do we see with an aerogenous route of pathogen in quadropeds?

Answer 36

cranioventral pneumonia

Question 37

what is bronchopneumonia?

Answer 37

extension from distal airways to alveoli

Question 38

how does pneumonia affect pulmonary function?

Answer 38

reduces area of effective gas exchange disruption of surfactant hypoxic vasoconstriction ventilation-perfusion mismatching

Question 39

what can chronic pneumonia result in?

Answer 39

fibrosis, bronchiectasis, abscess formation

Question 40

what can diffuse alveolar injury result from?

Answer 40

severe gram negative sepsis, burn injury, severe tissue trauma, or pancreatitis

Question 41

what is acute lung injury?

Answer 41

exudation of protein-containing fluid into the alveolar space and recruitment of activated neutrophils into the alveoli

Question 42

what does the repair phase of injury begin with?

Answer 42

formation of hyaline membranes

Question 43

how does pulmonary fibrosis lead to restrictive lung diseases?

Answer 43

decreased lung volumes and decreased compliance diffuse interstitial fibrosis

Question 44

how is pulmonary arterial hypertension manifested clinically?

Answer 44

increase in pulmonary vascular resistance and increased pulmonary arterial pressure

Question 45

what is alveolar emphysema?

Answer 45

enlargement of air spaces distal to terminal bronchioles resulting from destruction of alveolar and capillary tissue by proteolytic enzymes

Question 46

what is interstitial emphysema?

Answer 46

presence of air in connective tissue septa of lung and in subpleural tissue cattle and swine primarily, otherwise rarely of clinical significance

Question 47

what is secretory IgA important in?

Answer 47

virus/toxin neutralization prevention of bacterial and viral attachment to epithelial surface bacterial agglutination

Question 48

what can mucus hypersecretion be due to?

Answer 48

increased synthesis and release by goblet or submucosal glands goblet cell hyperplasia

Question 49

why does squamous metaplasia occur?

Answer 49

continued injury

Question 50

in whom can obstruction due to extensive hyperplasia of the bronchus associated lymphoid tissue occur?

Answer 50

swine sheep cattle rodents chronic mycoplasma infection

Question 51

what is diffuse alveolar injury often caused by?

Answer 51

gram negative sepsis burn injury severe tissue trauma pancreatitis

Question 52

what strategies do bacteria that are specialized to invade without prior viral infection use?

Answer 52

surface adhesions IgA-specific bacterial proteases bacterial products that inhibit ciliary motion

Question 53

who is embolic pneumonia common in?

Answer 53

ruminants and swine

Question 54

what causes the consolidation that occurs with pneumonia?

Answer 54

neutrophil exudates first neutrophils, lymphocytes, and fibrin