Respiratory physiology Flashcards
what part of the lung has the best ventilation perfusion ratio
hilum
what part of the lung has very little ventilation
apex
TV
500ml
IRV
3100ml
ERV
1200ml
RV
1200ml
IC
3600ml
FRC
2400ml
VC
4800ml
TLC
6-5 liters
type I aveolar cells in the lung
squamous (gas exchange)
type II aveolar cells in the lung make
[surfactant] phospholipids (dec. surface tension)
what keeps the lungs expanded decreasing surface tension
lipoprotein
hyaline membrane disease
no surfactant
during inspiration
diaphragm contracts and decreased pressure move air into lungs
decreased intrapleural pressure =
inspiration
partial pressure in alveoli is controlled by
- rate of absorption of oxygen into the blood
2. rate of entry of new oxygen into the lungs
what turns off inspiratory center before overexpansion of lungs
pneumotaxic center
this causes stretch receptors in the bronchii preventing over-stretching the lungs
herring - breuer relfex
prevents turn off of inspiratory center
apneustic center
boh reffect
co2 enters blood, causes o2 to dissociate from hemoglobin
haldane effect
co2 combines with hemoglobin = more bicarbonate ions
co2 in blood as
HCO3 (70%)
co2 as carbaminohemoglobin
20%
