lung volumes & alveolar ventilation Flashcards
Define the term ‘tidal volume’
- the air inhaled and exhaled in normal respiration in one breath
What amount of air (**in ml*) is the tidal volume?
500ml is inhaled and 500ml is exhaled
Define** inspiratory reverse volume** (IRV)
- the amount of air** in excess of tidal inspiration** that can be inhaled with maximum effort
- ie the amount of air inhaled after tidal volume inspiration
Define expiratory reverse volume (ERV)
the amount of air** in excess of tidal expiration** that can be exhaled with max effort
* ie the forceful expiration of air beyond tidal volume exspiration
Define residual volume
- the amount of air** remaining in the lungs after maximum expiration**
- air has to remain in lungs because otherwise the lungs would collapse
What is the purpose / function of the residual volume?
- keeps the alveoli** inflated between breaths **and mixes with fresh air on next inspiration
Define vital capacity (VC)
- The amount of air that can be exhaled with max effort after max inspiration (ERV +TV +IRV)
What is vital capacity used to assess?
- it is used to** assess strength of thoracic muscles as well as pulmonary function**
Define inspiratory capacity
- the maximum amount of air that can be inhaled after a normal tidal expiration (TV + IRV)
Define functional residual capacity (FRC)
- the amount of air remaining in the lungs after a normal tidal exspiration
Define the total lung capacity (TLC)
- the max amount of air that the lungs can contain
what is spirometry?
the measurement of lungs volumes and flow
what is the function of a spriometer?
any device used to measure lung volumes or flow
* different types eg bellow spirometer
Why cant total lung capacity (TLC), **functional residual capacity **(FRC) and residual volume (RV) be measured on a spirometer?
- this is because a spirometer only measures the volumes that can be inhaled or exhaled
What is the purpose of pulmonary function test?
what does the test provide? what does it determine?
- this test provides information on a patients lung function
- it can sense any abnormalities and monitor disease progression
- it can also determine fitness for surgical procedures