Respiratory Physiology Flashcards
West Lung Zones
-In zone 1 there is no pulmonary blood flow
-In zone 1 alveolar pressure is higher than arterial pressure
-In zone 2 ventilation is matched to perfusion
-In zone 2 arterial pressure is higher than alveolar pressure
-In zone 3 pulmonary blood flow is proportional to the arterial-to-venous pressure gradient
-In zone 3 venous pressure exceeds alveolar pressure
Anatomic dead space begins in the mouth and ends in the:
Terminal bronchioles
Contraction of the inspiratory muscles reduces thoracic pressure and increases thoracic volume. This is an example of what law?
Boyle’s Law
The diaphragm increases what part of the chest?
superior-inferior dimension of the chest
The external intercostals increase what part of the chest?
anterior-posterior diameter
Accessory muscles include?
sternocleidomastoid and scalene muscles
Active exhalation is carried out by what abdominal muscles?
TIRE-Transverse abdominis, Internal oblique, Rectus abdominis, External oblique
When does exhalation become active?
When minute ventilation increases OR with lung dx (COPD)
What is the least amount of vital capacity needed for an effective cough?
15mL/kg
What is alveolar pressure?
-Pressure inside the airway
-Slightly negative during inspiration and slightly positive during expiration
- Positive during forced expiration (including during pneumothorax)
What is intrapleural pressure?
Pressure outside the airway
Always a negative (-) value= keeps lungs inflated
What is Transpulmonary pulmonary pressure (TPP)
The difference between the pressure inside the airway and the pressure outside of the airway.
TPP= Alveolar pressure-Intrapleural pressure
If TPP is a positive value?
Airway stays open
If TPP is a negative value?
Airways collapses
