What is the primary determinant of airway resistance?
Airway resistance is the resistance to flow of air caused by friction with the airways, which includes the conducting zone for air, such as the trachea, bronchi and bronchioles. The main determinants of airway resistance are the size of the airway and the properties of the flow of air itself.
What determines airway resistance in the respiratory passageways?
Airway resistance refers to degree of resistance to the flow of air through the respiratory tract during inspiration and expiration. The degree of resistance depends on many things, particularly the diameter of the airway and whether flow is laminar or turbulent.
What conditions may affect lung compliance and airway resistance?
Factors affecting lung compliance include elasticity from the elastin in connective tissue and surface tension, which is decreased by surfactant production. Lung compliance participates in the lung-chest wall system by opposing the outward pull of chest wall compliance.
What three physical factors influence pulmonary ventilation?
Several physical factors that influence the efficiency of pulmonary ventilation are compliance, alveolar surface tension, and airway resistance.
What factors that influence airway resistance and how do they make that effects?
- Lung volume (increasing volume stretches and elongates the bronchi)
- Artificial airways (increase the length in the case of an ETT, or decrease it in the case of a tracheostomy)
What causes an increase in airway resistance?
Bronchospasm, mucus plugging, and edema in the peripheral airways result in increased airway resistance and obstruction. Air trapping results in lung hyperinflation, ventilation/perfusion (V/Q) mismatch, and increased dead space ventilation.
Which of the factors increases airway resistance and causes bronchoconstriction?
How does lung volume affect airway resistance?
Airway resistance changes with lung volume but not in a linear manner. Increasing the lung volume to above FRC only minimally decreases airway resistance. In contrast, as lung volume decreases from FRC, resistance rises dramatically and approaches infinity at RV.
What are the 3 factors that influence airway resistance?
Multiple factors can influence airway resistance, including airflow velocity, the diameter of the airway, and lung volume.
What is the most significant factor affecting airway resistance and why?
Factors which affect airway resistance by affecting airway diameter. These are obviously numerous. Nunn’s goes into overmuch detail regarding the sympathetic control of the airway smooth muscle, which has importance for bronchodilator therapy. There are of course numerous other factors.
How do you measure airway resistance?
Airway resistance is the ratio of driving pressure to the rate of the airflow in the airways. The most frequent methods used to measure airway resistance are whole-body plethysmography, the interrupter technique and the forced oscillation technique.
What effect would increasing airway resistance have on FEV1?
asthma) to exhale quickly due to the increase in airway resistance. As a result, the FEV1/FVC ratio will be much lower than normal, for example 40% as opposed to 80%. In the restricted lung, the FVC is again smaller than normal, but the FEV1 is relatively large in comparison.