Resp knowledge corrections Flashcards
intra- alveolar pressure before inspiration
= atmospheric pressure
intrapleural fluid cohesiveness plus +ve intrapleural pressure
holds lungs and thoracic wall in opposition
sub atmospheric intrapleural pressure
transmural pressure gradient across lung and chest wall, lungs expand outwards, chest squeeze inward in inspiration
accessory resp muscles
scalenous and sternocleidomastoid
spirometer
measures volume of air inspired and expired
radius of airway
determines resistance to airflow
intrapleural pressure increases in
expiration and decreases in inspiration
dynamic airway compression
increased intrapleural pressure during expiration compresses alveoli airway
alveolar ventilation
volume of air exchanged between atmostphere and alveoli/ min
blood flow faster where in lung
bottome
increased CO2
increased perfusion, increased airflow by decreasing airflow resistance
increased O2
increased ventilation
pulmonary vasodilatation
diffusion coefficient of Co2
20 x O2
most O2 in blood
bound to Hb not dissolved
PO2
determines Hb O2 concentration
Hb concentration decreases
O2 saturation normal
myoglobin
in skeletal and cardiac muscle
R shift in oxygen dissociation curve
decrease affinity for O2 and increased temp
co2 mostly transported
in blood as HCO3
what catalyses HCO3
carbonic anhydrase
CO2 binds to which part of Hb
globin
reduced Hb binds to
more CO2 than HbO2
haldane affect
o2 released at tissues
increased Hb affinity for CO2 so CO2 taken from tissues
inspiration caused by
dorsal resp group neurons
rhythm generated in
medulla
modified by pons
chemoreceptors
sense value of gas tensions
what diffuses across blood brain barrier
co2 not H+
