Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
5 Cards in this Set
- Front
- Back
|
work generated by respiratory muscles is to overcome what?
how much do respiratory muscles consume of oxygen during quiet breathing? during labored/hyperventilation? in dz pt? |
the elastic recoil of the lung
flow resistance of the airways
3-5% of total oxygen consumption, substantially more, can be 25-30%! |
|
|
what is work? classically and for lungs |
work = force x distance
work = pressure x volume, so integral of Pressure dVolume |
|
which areas represent the the work to overcome various parts.
how does this prove that expiration is no work? |
ABCDA: total work required for inspiration of one tidal volume ABCEA: to overcome airway resistance during inspiration AECDA: overcome lung elasticity during inspiration: triangle ACEFA: work to overcome airway resistance during expiration (it's the shaded area)
The work during inspiration to overcome lung elastic recoil is AECDA, the triangle. It is larger than the work required to overcome airway resistance during expiration. The work done during inspiration is stored as potential elastic energy, so during expiration that energy is enough to cover the work. |
|
what is the pt like? what notes about work differences? |
restrictive dz pt
overcoming the elasticity during inspiration is much higher. Ejecting is going to be intense too. |
|
what is the pt like? what notes about work differences? |
obstructive dz pt
Overcoming resistance is much more substantial both on inspiration and expiration
the AECDA work to overcome elasticity during inspiration is about the same as normal (in uncomplicated pt), but that's bad since so much expiration resistance. So basically all the shaded area outside the AECDA triangle has to be generated by expiratory muscles |
