Transition Week Flashcards
Functional Residual Capacity?
Volume of air left in lungs after normal, passive expiration.
FRC = Residual Volume + Expiratory Reserve Volume.
How does obesity affect FRC:
Decreases due to pressure on diaphragm etc.
How does COPD affect FRC:
Increase, emphysema causes more air-trapping. Elastic recoil of lung is lost.
What % of total lung capacity is FRC:
40%
Forced Vital Capacity?
Maximum volume of air that can be moved out during a single breath following a maximal inspiration.
FVC = IRV+TV+ERV
Total Lung Capacity?
Maximum volume of air that the lungs can hold at the end of maximum inspiration.
TLC = Vital Capacity + Residual Volumd
Can you measure residual capacity on spirometry?
NO
Therefore you also cannot measure total lung capacity this way
Where is respiratory rhythm generated?
in the medulla
Role of peripheral chemoreceptors in respiration?
Sense tension of oxygen and carbon dioxide and H+in th el
Role of peripheral chemoreceptors in respiration?
Sense tension of oxygen and carbon dioxide and H+in the blood
Role of central chemoreceptors in respiration?
Situated near surface of medulla on brainstem. Respond to H+ conc in CSF.
Hypoxic drive of respiration?
Effect via peripheral chemoreceptors. Stimulated when PO2 falls to low. Important in high altitudes.
Process of inspiration?
Active process.
Volume of thorax increases due to contraction of diaphragm. External intercostal muscle contraction lifts the rives and moves out the sternum.
Process of inspiration?
Active process.
Volume of thorax increases due to contraction of diaphragm. External intercostal muscle contraction lifts the rises and moves out the sternum.
Intrapleural pressure falls so air rushes in.
Forces promoting alveolar collapse?
Elasticity of stretched pulmonary connective tissue fibres.
Alveolar surface tension
