Chapter 37 - Pulmonary Ventilation Flashcards
Lungs are expanded & contracted in 2 ways
- Downward & upward movement of the diaphragm
2. Elevation & depression of the ribs
4 major functions of respiration
Pulmonary ventilation
Diffusion of O2 & CO2 between alveoli & blood
Transport of respiratory gases
Regulation of ventilation
Muscles of inspiration
Extrenal intercostals* - most important
Others that help:
Sternocleidomastoid
Anterior serrati
Scaleni
Muscles of expiration
Abdominal recti
Internal intercostals
The pressure of the fluid in the thin space between the lung pleura & the chest wall pleura
Pleural pressure
The pressure of the air inside the lung alveoli
Alveolar pressure
The pressure difference between that in the alveoli & that on the outer surfaces of the lungs
Transpulmonary pressure
A measure of elastic forces in the lungs that tend to collapse the lungs at each instant respiration
Recoil pressure
The extent to which the lungs will expand for each unit increase in transpulmonary pressure (if enough time is allowed to reach equilibrium)
Lung compliance
What are the determinants of the elastic forces of the lung tissue
Elastin & collagen fibers interwoven among the lung parenchyma
Elastic contractile force of the entire lungs
Surface tension elastic force
A surface active agent in water
Surfactant
Special surfactant-secreting epithelial cells
Type II alveolar epithelial cells
Most important components of surfactants
Phospholipid dipalmitoylphosphatidylcholine
Surfactant apoproteins
Calcium ions
The volume of air inspired or rxoired with each normal breath
Tidal volume
