The Lungs & their function

1. Obstructive diseases (Status ashmaticus, COPD)

characterized : 1) obstrction to airflow through airways,
2) prolonged expiration,
3) gas trapping
--> Hyperinflation
--> ↑ The FRC & the TLC
(TLC= total lung capacity, the maximum achiavable end-inspiratory lung volume)

2. Restrictive diseases

ex : chest wall abnormalities (e.g., scoliosis)
N-M problems (e.g., Phrenic n. injury)
Parenchymal diseases (e.g., interstitial lung disease, Pulmonary edema)
pleural effusions,
Pneumothorax,
extrathoracic problems(e.g., ↑ intraabd. Pr)
--> ↓ FRC, TLC
* 대개의 FRC 측정 방법은 Invasive하여 사용할수 없고
Plethymograp로 FRC의 변화를 비슷하게 측정할 수 있다.
Mechanics of Ventilation
Ventilation
: Repetitive creation of pr. gradients between ambient(mouth) & alveolar pr.
--> overcome flow resistance in airways
--> gas movement in & out of the Lungs…(생략)

1) during Inspiration : inspiratory m. expand the thoracic cavity

2) Active expansion cease : alveolar pr. quickly equalizes c ambient

3) end inspiration : inspiratory m. relax