14. CP Lung Volume DSA Flashcards
What is the normal value for:
Tidal Volume
500 mL
What is the normal value for:
Inspiratory Reserve Volume
3,000 mL
What is the normal value for:
Epiratory Reserve Volume
1,200 mL
(same as reserve volume)
What is the normal value for:
Reserve Volume
1,200 mL
(same as expiratory reserve volume)
What is vital capacity?
Total lung volume minus reserve volume
(Vt + ERV + IRV)
What is inspiratory capacity?
Capacity of air that can be maximally inspired following a normal exhale
IRV + Vt
Define Tidal Volume
the amount of air inspired pr expired in a single breath
can vary (increases with aerobic activity)
What is residual volume?
the volume of air that cannot be forced out
When you get the wind knocked out of you, you only have residual volume left (thus the gasping/etc)
What is inspiratory reserve volume?
additional volume inhaled greater than tidal volume
(forced inhalation, between quiet inspiration and max. inspiration)
What is expiratory reserve volume?
additional volume that can be exhaled greater than tidal volume (not including residual volume)
requires expt. muscles
(tidal volume plus forced exp. volume)
What is total lung capacity?
max volume to which lungs can be expanded with greatest effort
(TV + IRV + ERV+RV)
Define functional residual capacity
amount of air that remains in the lungs following a normal expiration
FRC=ERV+RV
(helps prevent collapse of lungs/dilutes toxins/reduces workload)
What is vital capacity?
amount of air that can be maximally inspired following a maximal expiration
IRV+VT+ERV
What influences lung volumes?
- Body size
- age (increased FRC, RV with increased age, FVC decreases with age)
- Posture (decreased FRC when supine)
- Sex
- Ethnicity
- Obesity (reduces all static lung volumes, esp. RV and FRC, but NOT TV)
- other pulmonary diseases
How do we measure residual volume with helium dilution?
inhalation of a known concentration (C1) of helium (insoluble in blood) from a known volume (V1)
Change in concentration allows for determination of V2 = FRC
