Lectures 3 and 4: Respiratory Flashcards
(55 cards)
Fibrosis lung compliance
Decreased
Fibrosis impact on expiratory volume
Volume present in the lungs after expiring a breath would be less than normal
Emphysema impact on lung compliance
Increased
Emphysema is a disease involving which fibers in lungs?
Elastic
Emphysema impact on expiratory volume
Volume present in lungs after expiring a breath would be more than normal
Functional residual capacity
Resting, or equilibrium, volume of the combined lung and chest wall system
Emphysema FRC impact
Increased
Fibrosis FRC impact
Decreased
What is lung compliance
Volume/Pressure; the ability of the lungs to stretch and expand
In an air filled lung, how does alveolar pressure compare to atmospheric pressure?
Equal
As the pressure outside the lung is made more negative the lung…
Inflates and its volume increases
What is the expanding pressure for the lungs?
Negative outside pressure (intrapleural space)
Lung hysteresis
Lung volume at any given pressure during inhalation is less than the lung volume at any given pressure during exhalation
The intrapleural space normally has a ______ pressure
Negative
The negative intrapleural pressure is caused by which 2 things
The elastic properties of:
The lungs
The chest wall
What prevents the lungs from collapsing and the chest wall from springing out?
Negative intrapleural pressure
Pneumothorax definition
When sharp object punctures intrapleural space, air is introduced in the space, and intrapleural pressure becomes zero
What are the two consequences of pneumothorax?
Lungs collapse
Chest wall springs out
Atelectasis definition
Lung/alveoli collapse
What is atelectasis due to?
No surfactant, so small alveoli have increased surface tensions and pressures and collapse
Parasympathetic stimulation causes what to resistance of air flow?
Increase
Sympathetic stimulation causes what to resistance to air flow?
Relaxation
Surfactant defintion
A mixture of phospholipids that line the alveoli and reduce their surface tension. By reducing surface tension, surfactant reduces the collapsing pressure for a given radius
What about surfactant makes it decrease surface tension in the alveoli?
The attractive forces between adjacent molecules of liquid are strong than the attractive forces between molecules of liquid and molecules of gas in alveoli
