Ch 12 Pt3 Flashcards
Inspiration review:
Always an active process
-diaphragm contracts and flattens
-external intercostals contract, expanding ribcage
-increased intrapulmonary pressure inside chest cavity and lungs
Expiration Review
Active during forced, passive during rest
-diaphragm relaxes and moves back up against lungs
-external intercostals relax, ribcage lowers
-decreased volume inside chest cavity and lungs, decreases pressure
TV or Vt
Tidal volume
-amount of air inhaled or exhaled per breath
-around 0.4 to 1L
IRV
Inspiratory reserve volume
-inspiring as deeply as possible following a normal inspiration
2.5 to 3L above inspired tidal air
-allows increase/ decrease in tidal volume
ERV
Expiratory reserve volume
-after a normal exhalation, continuing to exhale and forcing as much air as possible from the lungs
1 -1.5 L beyond normal breathe out
FVC
Forced vital capacity
-total volume of air voluntary moved in one maximal breath
-largest amount of air that can be exhaled following a maximal inhalation
FVC= TV+ IRV + ERV
4-5L in young males, 3-4 in young females
RLV
Residual Lung Volume
-amount of air left in the lungs after a forced max exhalation
-allows continuos gas exchange between alveoli and capillaries to prevent changes in blood gases
0.8 to 1.2L healthy college female
0.9 to 1.4L healthy college male
TLC
Total lung capacity
-maximum amount of air the lungs can hold
4-6L remain
TLC+ RLV+ FVC
-differences because of size, number of working alveoli
TLC
Total lung capacity
-maximum amount of air the lungs can hold
4-6L remain
TLC+ RLV+ FVC
-differences because of size, number of working alveoli
Sex differences in lungs:
Males are larger, therefore values are larger
-females have a reduced lung size
Prismatic gemoetry in females: smaller in cages and lungs
Males gave pyramidal geometry
Sex differences:
Females have smaller airway diameter, smaller diffusion surface, lower static and dynamic lung capacities
Predicted values of VO2 based on height and weight does not account for:
Sport training, health status (smoking, asthma), body composition (abdominal fat, breast tissue), genetics
Can sport training increase total lung capacity
No, alveoli are the main factor for TLC
-land training doesn’t increase alveolar function/ number, but swimming/ water training possibly could
-due to less oxygen available, respiratory muscles are breathing in resistance against external factors
Dynamic Lung Volumes
Pulmonary ventilation capability is dependent on continued airflow, not just a single breath
FEV: FVC Ratio
Forced Expiratory Volume: maximal airflow measured over 1 second (FEV1.0)
FEV1.0 / FVC indicates pulmonary airflow capacity
-range of 70-90% , 85% in healthy individuals
Reflects pulmonary expiratory power and overall resistance to air movement upstream
Minute Ventilation
Amount of air breathed in 1 min
Measured in (L/min or ml/min)
-includes air from conductive zone and respiratory zone
Represented by VI -inspired minute ventilation and
VE- expired minute ventilation -like cardiac output (Q=HRxSV)
-VE= Breath/ min x TV
Minute Ventilation is also equal to
Tidal volume (ml/breath) x frequency of rate (breath/min)
Ve= VT x F
At rest: 12-15 breaths/min, 400-600ml per breath
VA (big A)
Alveolar Ventilation: amount of air available for gas exchange (only from respiratory zone)
: [VT (ml/breath) - dead space (ml/ breathe)] x F (breaths/ min)
-what’s getting down to the alveoli
VA= VT- dead space x F
Alveolar Ventilation is greater than Minute Ventilation?
False
Linda is running in a race and has a tidal volume of
1.5L per breath and a breathing frequency of 40.
She is a young active non-smoker with an estimated
dead space of 120 ml.
Calculate her Alveolar Ventilation?
VA= VT (ml/breath) - dead space x F
VA= (1500ml/ breath) -120mL x 40bpm
=55.2 L/min
Minute or alveolar ventilation can be increased by:
Increasing depth (VT) or rate/ frequency of breathing
-depth is more efficient, but will eventually plateau
Why do we see increase in ventilation during exercise?
To allow for more gas exchange (O2 and CO2)
Vt
Tidal Volume: amount of air inhaled or exhaled per breath
Residual Volume
RLV/ RV: amount of air left in the lungs after max exhalation
FVC
Forced Vital Capacity: Largest amount of air that can be exhaled following a max inhalation
TLC
Total Lung Capacity: max amount of air the lungs can hold
Highest values of air to lowest order:
TLC> FVC> RLV> VT
