Resp Flashcards
Alveolar pressure during 1)inspiration 2)expiration
Pleural pressure during 1)at beginning of inspiration 2)at the height of inspiration
1) -1cm of H2O —>alveolar air is rich in O2
2) +1cm of H20 —-> alveolar air is rich in CO2
1)-5 cm of H20 2)-7.5 cm of H2O
Tidal volume (VT).
- Inspiratory reserve volume (IRV).
- Expiratory reserve volume (ERV)
- Residual volume (RV).
- Dead space
Tidal volume (VT) is the volume inspired or expired with each normal breath.
- Inspiratory reserve volume (IRV) is the volume that can be inspired over and above the tidal volume. is used during exercise.
- Expiratory reserve volume (ERV) is the volume that can be expired after the expiration of a tidal volume.
- Residual volume (RV) is the volume that remains in the lungs after a maximal expiration. cannot be measured by spirometry.
- Dead space
a. Anatomic dead space is the volume of the conducting airways. is normally approximately 150 mL.
Lung capacities
- Inspiratory capacity
- Functional residual capacity (FRC)
- Vital capacity (VC),
- Total lung capacity (TLC)
- Inspiratory capacity is the sum of tidal volume and IRV.
- Functional residual capacity (FRC) is the sum of ERV and RV.
is the volume remaining in the lungs after a tidal volume is expired. includes the RV, so it cannot be measured by spirometry. - Vital capacity (VC), or forced vital capacity (FVC) is the sum of tidal volume, IRV, and ERV.
is the volume of air that can be forcibly expired after a maximal inspiration. - Total lung capacity (TLC) is the sum of all four lung volumes.
is the volume in the lungs after a maximal inspiration. includes RV, so it cannot be measured by spirometry.
Inspiratory and expiratory muscles when are they used
Muscles of inspiration
- Diaphragm is the most important muscle for inspiration.
- External intercostals and accessory muscles are not used for inspiration during normal quiet breathing.
are used during exercise and in respiratory distress.
B. Muscles of expiration
Expiration is normally passive.
Because the lung–chest wall system is elastic, it returns to its resting position after inspiration.
Expiratory muscles are used during exercise or when airway resistance is increased because of disease (e.g., asthma).
1. Abdominal muscles.
2. Internal intercostal muscles pull the ribs downward and inward.
Lung compliance
It’s relation to elasticity and stiffness
It’s the slope of ______ curve
C=V/p
describes the distensibility of the lungs and chest wall
Inversely related to elasticity and stiffness
Slope of volume pressure curve