Respiratory Volumes: Karius Lecture Flashcards
(16 cards)
Tidal volume
amount of air inspired/expired in a single breath
varies with circumstance (resting versus exercise)
Inspiratory Reserve Volume
IRV
amount of air that can be breathed in after tidal volume
Expiratory Reserve Volume
the amount of air that can be expired in addition to tidal volume
requires activation of expiratory muscles (active expiration)
Residual volume
no matter how hard you try, you cannot voluntarily force this air
a c
having the wind knocked out of you, forced out
a capacity is defined as
the sum of two or more of the respiratory volumes
there are four capacities
are capacities static?
no, they are influenced by size, gender, and age: what does matter is the % predicted
Vital capacity
the sum of the IRV, Vt, and ERV
does not include RV, so it can be measured using spirometry
Inspiratory capacity
Vt + IRV
inhale as deeply as you can
the total volume of air you can inhale from a normal resting point
includes tidal volume and IRV
DOES NOT INCLUDE RV so it CAN be measured using spirometry
Functional residual volume
FRC = ERV + RV
all the air that remains in the lungs at the end of a normal (passive) respiration
includes RV, so cannot be measured with spirometry
Total Lung capacity
TLV = ERV + IRV + Vt + RV
cannot be measured by spirometry
Dead space: definition
areas of lungs that receive air but not blood
work done in dead space is
mostly wasted
Three kinds of dead space
anatomical, alveolar and physiologic
Anatomical dead space
conducting airways that were not supposed to exchange gases
Alveolar dead space
alveoli that get air, but do not get blood.
no gas exchange occurs here: there is no blood to exchange with
so the work it took to tget the air into these alveoli is wasted
physiological dead space
the sum of anatomic and alveolar dead space
