UNIT 3: Respiratory Physiology Flashcards
compare/contrast quiet inspiration vs forced inspiration
quiet inspiration –> aka rest breathing… diaphragm and external intercostals contract (and interchondral internal intercostals)… diaphragm accounts for 60% of inspiratory capacity
forced inspiration –> inc oxygen needs…. requires activation of the accessory muscles of inspiration… diaphragm contracts, abdomen protrudes
compare/contrast quiet expiration and forced expiration
quiet expiration —> involves passive forces only (no active forces)… gravity pulls ribs back to rest… the lungs are highly elastic, when stretched by inc thoracic volume they will return to original shape and size when released
forced expiration –> requires muscles contraction and passive forces, compresses abdominal viscera and thorax
what are the two diff elements that can be measures during respiration? how can they be measure?
- lung volume, w spirometry
- pressure, w manometery
what is respiratory rate?
- number of respiratory cycles per min (breaths per min, BPM)
what is volume? volume capacity?
- size or extent of a 3D space
- optimum or max volume
spirometer
- measures volume of water displaced by respiration
- measured in cubic cm (cc)
tidal volume (TV)
volume of air exchanged (inspired and expired) in one respiratory cycle
dependent on body/thorax size
450 cc for young adult female, 600cc for young adult male
inspiratory reserve volume (IRV)
- max volume of air that can be inspired above normal (i.e quiet) inspiratory tidal volume
- female = 1950cc, male = 3000cc
expiratory reserve volume (ERV)
- max volume of air that can be expired below normal expiratory tidal volume
- female = 800cc, male = 1200cc
residual volume (RV)
- volume of air remaining in lungs after a maximal forced expiration
- includes dead air in upper resp tract
- female = 1000cc, male = 1200cc
inspiratory capacity (IC)
- total amount of air that can be inspired after a tidal expiration
TV + IRV - approx 3000cc
functional residual capacity (FRC)
- amount of air remaining in lungs after tidal expiration
ERV +RV
Vital capacity (VC)
total amount of air that can be forcibly expired after a maximal inspiration
TV + IRV + ERV
- approx 4000cc
total lung capacity
total amount of air in the lungs after a maximal inspiration
TV+ IRV+ ERV+ RV
approx 5100cc
how does vital capacity change w age?
- inc 20 mL per year in adulthood to 20 years
- begins to decline at about 25 years old
All lung capacities except ___ decline because…
- Residual volume
- reduced elasticity: reduced ability to inflate the lungs, RV inc
- bronchiole diameter begins inc
- alveolar wall begins thickening
pressure
force exerted on walls of a chamber by gas molecules
manometer
measures number of cm or inch of water - cm/H2O
pressure is dependent on ____
- area
- pressure = force/area
- as area inc pressure dec
- as area dec pressure inc