Lecture 17 Flashcards
What occurs to create a pressure gradient?
Gas will move from high pressure to low pressure.
Inhalation
Volume increases while pressure in the lungs decreases.
Exhalation
Volume decreases, the pressure inside lungs increases
What is the direction of the airflow determined by?
The difference between atmospheric pressure and intrapulmonary pressure (inside the lungs)
What are the two opposing forces that must be overcome to take a breath
The stiffness of the lungs and the resistance of the airways to the lungs
What is lung stiffness related to?
Compliance
What is compliance?
Change in lung volume over the change in pressure
What does low compliance indicate?
Stiff lungs
Pulmonary fibrosis
Thickening and scarring of the alveolar membranes. Can arise from chronic inflammation or exposure to industrial chemicals.
What is surfactant produced by?
Alvolar type 2 pneumocutes
How does surfactant reduce surface tension in alveoli?
Makes them easier to expand.
What is the main area of airway resistance?
Bronchi
Tidal volumes
Volume of air moved in and out during normal quiet breath
Inspiratory reserve volume
Extra volume that can be inhaled over and above the tidal volume.
Expiratory reserve volume
Extra volume that can be exhaled voluntarily after completion of a normal, quiet respiratory cycle
