1. Lung ventilation Flashcards
how much fluid in pleural space?
15ml
compare direction of lung and chest wall elastic recoil
lung-inward
chest wall-outward
why is intrapleural pressure negative throughout inspiration and expiration?
keep alveoli/lungs from collapsing
what creates the negative pressure in inter pleural space?
opposing forces of elastic recoil of lungs and chest wall
compare intrapulmonary pressure to atmosphere during respiration
negative on inspiration
positive on expiration
transpulmonary pressure
difference between intrapulmonary and intrapleural pressure
compliance vs elastic recoil
compliance: how easy to stretch
recoil: how much snap back
how is the resistance in down stream airways kept low?
tubes are connected in parallel, which creates alternative routes
how do bronchioles stay open in expiration?
radial traction of surrounding alveolar walls
what is emphysema?
abnormal, persistent enlargement of air spaces (distal to terminal bronchiole), with destruction if alveolar walls by proteases
reduced elasticity, reduced SA for gas exchange
chest deformity in emphysema
barrel chest
chest XRAY deformity in emphysema
-lungs hyper inflated, so more ribs visible in lung field
-diaphragm flattened
what is lung interstitium?
space between alveolar epithelium and capillary endothelium
what does interstitium contain?
-elastin fibres
-collagen fibres
-fibroblasts
-matrix substance
lung fibrosis symptoms
-breathlessness
-dry cough (no mucus production)
-history (smoking, RA, builder, farmer, methotrexate)
