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Unit 4 Respiratory
Respiratory System Key Terms
Term | Definition |
---|---|
Diffusion | The movement of oxygen and carbon dioxide across the alveolar-capillary membrane. It takes place between the gas in the alveolar spaces and the blood in the pulmonary capillaries. |
Elastance | he extent to which the lungs are able to return to their original position after being stretched or distended. |
Hypoxemia | Deficient oxygenation of the blood. |
Hypoxia | A broad term referring to diminished availability of oxygen to the body tissues. |
Lung compliance | The ability of the lungs to distend in response to changes in volume and pressure of inhaled air. Lung compliance first increases and then decreases with age as the lungs become stiffer and the chest wall more rigid. |
Perfusion | The delivery of fluid through the blood vessels to body tissues. |
Pulmonary hygiene | Methods used to clear secretions from the airways. |
Resistance | The force working against the passage of air. The major determinant is the radius of the airway. |
Respiratory failure | An abnormality of gas exchange with either an excess of carbon dioxide or a deficit of oxygen, or both. |
Shunting | Shunting: The diverting of blood so that it does not take part in the gas exchange at the alveolar sites. When it occurs, blood enters the left side of the heart without being oxygenated. It is, therefore, a possible cause of hypoxemia. |
Surfactant | A complex lipoprotein produced by cells lining the alveoli, which lowers surface tension within the alveoli. It prevents collapse of the lung by stabilizing the alveoli and decreasing capillary pressures. |
Ventilation | The movement of air from the external environment to the gas exchange units of the lung. It can be spontaneous or done by a mechanical ventilator. |