Lecture 5: Resistance Flashcards
elastic resistance
related to compliance and tendency of lungs to collapse when lung volume incrd above FRC
Airway resistance
due to properties of tubes oppsoing movement of air through them- depends on lim volume and turbulence
Airway resistance depends on (5)
1- rate of airflow 2- driving pressure 3- diameter of tube 4- length of tube 5- Viscosity/density of gas
Radius and length change throughout the system
get progressively smaller but mroe airways due to branching
Total resistance of the lung decreases or increases as it gets deeper into the lung?
Decreases
Resistance decreases with?
increases lung voolume
Turbulence
disruption of smooth flow profile due to high airflow and branch points
Resistive pressure
dufference between elastic recoil and total pleural pressure
Alveolar pressure
negative during inspiration, 0 when no airflow
Flow is?
effort dependent
more airflow wth greater effort during inspiration
Effort indeoent flow limitation
no matter how hard you try to expire, cant increase flow beyond linear slope of flow rate decrease; due to relationship between R, compliance and expiratory driving pressure during expiration
Inspiration
pleural pressure becomes more negative, alveolar pressure becomes negative equal to chance in pleural pressure, pressure along airways becomes more negative as it approaches the mouth
Expiration
pleural pressure less negative, alveolar pressure positive, trans pulmonary pressure decrease as you get near the mouth
Pleural Pressure has a ________ effect on airways
compression
Equal Pressure Point (EPP)
point at which pressure in airway and pleural space equal
