Respiration Lecture 04: Compliance, FRC, and Respiratory Volumes Flashcards
what causes heart sounds?
turbulence in the tube system
2 forces that affect ability of lung to inflate
compliance + resistance
What happens when stretching force of lung is released?
elastic tissue springs back into rest position
minimal volume
minimum volume lungs can be at before they collapse
as you increase lung volume, is more or less pressure required to inflate further?
more
slope of pressure volume curve =
compliance
stiffening the lung _______ compliance
decreases
emphysema causes _____ compliance. Fibrosis causes ________ compliance
emphesema –> increased
fibrosis –> decreased
net compliance of lung =
lung elastic recoil + surface tension
lung hysteresis
lung pressure and volume shows inflation and deflation curves that follow different paths
elastic forces of chest wall work in _______direction of the lung
opposite
Negative pressure must be applied to chest wall for it to ______
decrease in volume
Must apply ________pressure for chest wall to expand
positive
natural resting point of chest
very large volume (occurs during pneumothorax)
Functional Residual Capacity
Rest position when all compliance forces are in balance. Includes air left over in lungs after reaching normal rest point.
FRC = Residual volume + expiratory reserve volume
airway pressure
pressure measured when looking at total respiratory system including lung AND chest wall. Depends on the combined elastic forces of the lung and chest wall
compliance of the respiratory system (Cr)
the result of the balance of the lung and chest wall compliance
A major factor in tidal volume and associated Ppl
compliance
How does compliance affect FRC?
Decreased lung compliance will decrease FRC and increase collapsing force by the lung.
Resting lung volume =
FRC
vital capacity
amount of expired when starting from maximum inspiration and ending at maximum active exhalation
total lung capacity
vital capacity + residual volume
Which muscles are used above, at, and below FRC?
above - diaphragm
at- none
below - abd. muscles
inspiratory capacity
how much you can inhale starting from FRC
expiratory reserve volume
air you can actively expel out beyond FRC
What is net force for chest wall pulling out and lungs pulling in at residual volume?
pull out (chest wall wins over lungs)
What is net force for chest pulling out and lungs pulling in at FRC?
net force = 0
what is net force for chest pulling out and lungs pulling in at end of tidal breath (end of normal inspiration)?
net collapsing force
What is net force for chest pulling out and lung pulling in at 70% TLC?
net collapsing force, airflow out of lung
What is net force of chest pulling out and lung pulling in at TLC?
Huge collapsing force. Both chest wall AND lungs want to collapse
