Work of Breathing Flashcards
What does the trachea divide into?
Right and left bronchi.
Which nervous system supplies some aspects of the thorax?
The somatic nervous system.
Why is residual volume of air left after exhaling?
Because to exhale, the elasticity of alveoli must overcome the elasticity of the thorax wall. A balance occurs between these two forces, but eventually no more air can leave, leaving the residual volume behind.
What is the tidal volume?
Normal breathing.
What is the inspiratory reserve volume?
Remaining air left in lungs after quiet breathing.
What is the exploratory reserve volume?
Air you can exhale after quiet breathing.
What is the residual volume?
Air left after full exhalation.
What is the vital capacity?
Volume of air that can be expelled after the deepest possible inhalation.
What is the minute volume?
Air inhaled in one minute.
How is the minute volume calculated?
Tidal volume x respiratory frequency.
Why is helium used to measure lung volumes?
It isn’t taken up by blood or lost from alveoli.
What is lung compliance?
Increase in lung volume per unit increase in pressure.
What is lung elastance?
Reciprocal of compliance - pressure needed to inflate lungs by one unit of volume.
What is airway resistance?
Pressure needed to drive one unit of air flow through conducting airways.
How is airway resistance calculated?
Pressure divided by flow of air.
