Flashcards in Lec 13 Deck (37):
What is definition of asthma?
episodic obstruction characterized by reversible airway narrowing
What is pathogenesis of asthma?
- development allergic phenotype in susceptibl individual characterized by TH2 lymphocyte IL 4/5/9/13 which orchestrate inflammatory response
What are major effects cells of asthma?
What is extrinsic asthma?
due to type 1 hypersensitivity
either atopic [allergic] or occupational
What is intrinsic asthma?
due to non-immune cause
aspirin ingestion, pneumonia, cold, stress, exercis
What is status asthmaticus?
unremitting attacks due to exposure to previously sensitized antigen
What do you see grossly in asthma?
- overdistended lungs
- thick mucus plugs in proximal bronchi
What do you on microscopy in asthma?
inflammation --> EOSINOPHILS
thickened basement membrane!!
- mucus plugging
- increased goblet cells
- bronchial smooth muscle hypertrophy
How do you diagnose asthma?
PFTs including methacholine provocation + bronchodilator response
What is DLCO in emphysema? in pure chronic bronchitis?
emphysema = low DLCO
pure chronic bronchitis = normal
What is emphysema?
- permanent enlargement of airpsoaces distal to terminal bronchole and destruction of their walls
results in diminished expiratory drive and loss of tethering of small airways
What is centriacinar emphysema?
- central/proximal parts of acini affected; distal spared
- both emphysematous = normal airspaces exist within same acinus / lobule
usually upper lobe, heavy smokers
What is panacinar emphysema?
enlarges uniformly acini from level of respiratory bronchiole to terminal bronchiole
pan = entire acinus but not entire lung
What is paraseptal emphysema?
proximal portion of acinus is normal but distal involved
emphysema more striking adjacent to pleura
more severe in upper half of lungs
can cause spontaneous pneumothorax in young adult
What type of emphysema can cause spontaneous pneumothorax in young adult?
What are 2 subtypes of centriacinar emphysema?
- smoking related
- mineral dust [coal] associated
What is clinical of alpha 1 antitrypsin deficiency?
- early onset emphysema [< 45 yo]
- unexplained liver disease + possible cirrhosis
What is bullous emphysema?
any form that produces blebs/bulla = airspaces > 2cm
often subpleural near apex
can rupture --> pneumothorax, hemorrhage
What is chronic bronchitis?
hypersecretory process = non-specific pathologic changes
changes in mucus glands and too much mucus secretion in airways
have more infections, purulent sputum, hypercapnia, hypoxia than emphysema
How does tobacco lead to chronic bronchitis?
tobacco interferes with ciliary action
directly damages airway epitheilum and inhibits ability of WBCs to clear bacteria
What is microscopic morphology of early + later chronic bronchitis?
early: hyper-secretion of mucus in large airways; hypertrophy of submucosal glands
later: increase goblet cells in small airways; excess mucus production + airway obstruction; increased Reid index
What is definition of bronchiectasis?
pathologic irreversible dilatation of one or more proximal bronchi due to destruction of support structures of bronchial wall
can be localized but usually diffuse
What causes localized bronchiectasis/
obstruction due to tumor, foreign body, mucus
What causes diffuse bronchiectasis?
CF, immunodeficiency, kartageners
necrotizing pneumonia [staph or TB]
What is pathogenesis of bronchiectasis?
- PMNS/cell products overwhelm the bronchial wall
- impaired clearance mechs
What do you see on gross pathology in bronchiectasis?
- dilated tortuous easily collapsible airways often extending to visceral pleural surface
How does bronchiectasis cause obstruction?
- collapse of dilated airways with expiration = floppy
- poor air movement --> air just spins around not in and out
- excess secretions
What do you see in bronchiectasis on histology?
fibrosis, inflammation, loss of cartilage
What is bronchiolitis?
inflammatory response to injury of small airways
can have inflammation/fibrosis in diffuse or nodular fashion
What kind of cells in small ariways?
simple columnar [ciliated and non-ciliated]
few neuroendocrine cells
What diseases can small airway disease be associated wtih?
- hypersensitivity pneumonitis
What do you see in small airway disease?
adjacent lung have have foamy macrophage accumulation + dilation of adajcent bornchioles
What things cause acute small airway disease?
infection, fume exposure, aspiration, wegener's
What thigns cause chronic small airway disease?
bronchiectasis, collagen vascular disease, IBD, aspiration
What is constrictive vs intralumenal bronchiolitis?
constrictive = in wall itself
intralumenal = within lumen
WHat is constrictive bronchiolitis?
subepithelial collagen deposits --> airway narrowing + constriction
secondary to chronic airway damage with abnormal healing response
see w/ chronic transplant rejection