Respiration Physiology Part 4 Flashcards
What is Tidal volume (TV)?
(TV) : the volume of air inspired or expired
during restful breathing
500mL
What is Inspiratory Reserve Volume (IRV) :
: is the maximum extra volume of air that can be inspired over an above the normal tidal
volume.
3000mL
What is Expiratory Reserve Volume (ERV):
amount of air in excess
of tidal expiration that can be exhaled with maximum effort
What is Residual Volume (RV):
the volume of air that can not be
expelled, allows gas exchange between breaths (1200ml)
What is Vital Capacity (VC)
• Maximal volume expelled after maximal inspiration
What is the formula for Vital Capacity?
ERV+TV+IRV
What is the vital capacity of a normal adult?
: 3 ~ 5 L
What is the VC used for?
To assess strength of thoracic muscles and pulmonary
function.
When is VC reduced?
in both obstructive and restrictive respiratory diseases
What is forced Vital Capacity?
the volume of air expelled by a forced maximal expiration from a position of full inspiration as
soon as possible
What is forced expiratory volume (FEV):
the maximum volume expired
Didn’t know how to make a question out of this 🥲
FEV1/FVC 80%
FEV2/FVC 96%
FEV3/FVC 99%
Normal value:
FVC = VC
1st sec. (FEV,) – 83%
2nd sec. (FEV2) – 96%
3rd sec. (FEV3) – 99%
*FEV (forced expiratory volume)
When does Reduction of the FEV1 occur?
In obstructive lung disease
What happens to the FEV1 ratio of restrictive lung disease patients?
• The FEV1 ratio may be increased to >0.85 .
What is Inspiratory Capacity?
• Maximum amount of air that can be inhaled after a normal tidal expiration (TV+IRV)
3500mL
What is Functional residual capacity (FRC)?
Amount of air remaining in the lungs after a normal tidal expiration (RV+ERV)
2400mL
What is Total lung capacity (TLC)?
• Maximum amount of air the lungs can contain (RV+VC)
5900mL
What is Minute ventilation volume (Ve)
• amount of air inspired (or expired) during one minute
What is the formula for Minute Ventilation Volume?
Ve=respiratory rate x tidal volume
= 12 × 500 = 6000 mL/min
What is Alveolar ventilation
The rate at which new air
reaches in the gas exchange area
What is dead space?
space in the respiratory passages where no gas exchange takes place
There are three kinds
•Physiologic dead space
• Anatomic dead space
• Alveolar dead space
What is the formula for Alveolar ventilation (Va)?
= respiratory rate × (tidal vol.- dead space vol.)
= 12 breaths/min × (500-150) ml/beat
= 4200 ml/min
What are the two types of gas exchange?
•Pulmonary gas exchange
• Tissue gas exchange
What is pulmonary gas exchange?
The exchange of gases (oxygen and carbon dioxide) between the alveolar air and the pulmonary capillary blood.
What is tissue gas exchange?
The exchange of gases between blood and the body’s tissues at the cellular level.
What is rate of diffusion directly proportional to?
•Partial pressure (concentration gradient)
• Surface Area
• Solubility coefficient
• Temperature
What is rate of diffusion inversely proportional to?
• Distance of Diffusion
• Molecular Weight
Changes in the
concentration of dissolved gases are indicated as the
blood circulates in the body
What is oxygen converted to in Cells?
What is the byproduct of fuel catabolism in cells?
Oxygen is converted to water in cells
Cells release carbon dioxide as a byproduct of fuel catabolism.
Characteristics of diffusion of gases in liquids
The amount of gas dissolved will be directly proportional to the
partial pressure of the gas. • Diffusion equilibrium will be reached only when the POz in the
liquid is equal to the POz in the gas phase.
What does 1L of arterial blood contain?
3 ml of O2 physically dissolved (1.5%)
197 ml of 02 bound to hemoglobin (98.5%)
Total O2 content is 200mL
What is the measure of O2 carried to tissues per minute
O, carried to tissues/min = 5 L/min x 200 ml 02/L
= 1000 ml 02/min
