2-4 respiratory physiology Flashcards
active forces
requires a muscular effort
primary muscles = diaphragm & intercostals
passive forces
body moves due to other forces outside the body
gravity, elasticity, & torque
tidal breathing
contraction of diaphragm & external intercostals increases size of thorax
active inspiration, passive expiration
—– gravity pulls thoracic cavity, torque unrotates ribs back to neutral
500-700 cc of air exchanged / cycle
action of internal interosseous intercostals
origin = top of bottom rib
insertion = bottom of top rib
inserted at an angle /
longer lever on top = superior rib will move more
ribs will depress - expiration
attach to ribs & cartilage (pull on cartilage)
external intercostal
origin = bottom of top rib
insertion = top of bottom rib
inserted at an angle \
longer lever on bottom = inferior rib will move more
ribs will expand - inspiration
only attach to ribs
measuring respiration
spirometer
lung volume = smallest unit
lung capacity = combinations of volumes
tidal volume
volume of air exchanged during one quiet respiratory cycle
primary muscles
increases during work & varies depending on age & size
inspiratory reserve volume
inhale, hold, inhale again – amount of air that can be inhaled the 2nd time
secondary muscles - tense, shoulders back
1500-2500 cc
expiratory reserve volume
exhale, hold, exhale again – amount of air that can be exhaled the 2nd time
abdominal muscles - curl up to hold at bottom of expiration
1000 cc
residual volume
quantity of air that remains in the lungs & airways after maximal expiration, even after death
not present in newborns
1100 cc
dead air space
air in passageway that cannot be involved in gas exchange because there are no alveoli
included in residual volume
150 cc
vital capacity
quantity of air that can be exhaled after u breathe in as deep as u can
related to body size
tidal volume + inspiratory reserve volume + expiratory reserve volume - how much air you can get in & out of the body
important for speech
4000 cc
functional residual capacity
quantity of air in the lungs & airways at the resting expiratory levels
expiratory reserve volume + residual volume
total lung capacity
quantity of air the lungs are capable of holding at max inhalation
equal to sum of all lung volumes
inspiratory capacity
max volume of air that can be inhaled form the resting expiratory level
tidal volume + inspiratory reserve volume
