L23 Disease of Lung Parenchyma II Flashcards
Why is the R cranial lobe predisposed to inflammation/ Dz in pigs and cows
it arises from the tracheal bronchus so is more likely to receive foreign material
plus their lungs have interlobular septa so then they’re fuccked w/ infection b/w poor collateral vent/ circ
Why are I pneumoctues vulnerable
They are terminally differentiated
Large SA & little anti-oxidants so predisposed to hypoxic damage
Describe defence mechanisms of type II pneumocystis
phagocytosis division & differentiation into I or II reabsorb oedema (Na pump) anti oxidant agglutination & opsonisation bind endotoxin
How do pulmonary macrophages come into lungs
recruited from blood
slow mitotic division interstitial macros
Describe acute phase pneumonia
active hyperaemia
vasodialtion
neutorphils
What is happening in lungs after a few days with pneumonia
Type IIs are trying to repair the basement membrane & type I epithelium
Describe what is happening in the lungs after a week with pneumoains
Grey phase pneumonia
clearing of exudate
hyperaemia subsides
what are the typical gross features of bronchopneumonia
cranioventral inflame at broncho-alveolar junction where slow flow suppurative mild-mod progressive
What are typical gross creatures of lobar pneumonia
whole lobe affected fulminant (sudden & v severe) fibrinonecrotising \+ necrosis due to being due to toxin releasing bacteria \+/- pleuritis --> spreads \:(
e.g. horses more likely to get pleuropneumonia (pathogen based- higher bacto load)
What are typical gross features of interstitial pneumonia
Can be either inhaled or haematogenous (generally latter)
diffusion, patchy
thickened alveolar walls so meaty, enlarged,
atelectasis
When you squeeze a lung with lobar pneumonia, what is likely to come out?
prob not much as highly fibrinous
why do cow pig pneumonias generally persist
poor collateral ventilation so can’t cough the pneumonia up and get ride of path
What are some important causes of lobar pneumonia
manheimia haemolytica
pasteuralla multicoda
How might one distinguish between a bronchopneumonia and an bronchointerstitial pneumonia histologically?
grossly will be rather indestinguiable (cranioventrla, inhaled pathogens)
however the latter will have injury not only to distal bronchioles but also alveolar walls
Leukocytes accumulate in peribronchiolar CT and alveolar interstitium
what are some causes of bronchointerstial pneumonia
mycoplasma spp influenza virus parainfluenza corona virus herpesvirus
