Pleural Pressures during respiration Flashcards
Are the alveolar and atmospheric pressures greater or lower than the intrapleural pressures?
Greater
What happens to the air in a tension pneumothorax?
The intrapleural pressure exceeds the atmospheric pressure, leading to a collapse of the ipsilateral lung.
What happens to the mediastinum in a tension pneumothorax?
The mediastinum shifts away from the pneumothorax
What happens to the heart in severe cases of pneumothorax?
The intrapleural pressure can compress the heart and surrounding vasculature, reducing cardiac output and venous return. If untreated can lead to cardiac arrest.
What components within the thorax cause an inward pull of the lung tissue?
The elastic tissue of the lungs and the surface tension of the alveolar fluid
What components within the thorax cause an outward pull of the lung tissue?
The pleura fluid and thoracic wall cause surface tension which pulls the lung outward.
What cells monitor the pleural fluid?
The mesothelial cells
What system drains the pleural fluid?
The lymphatic system
Why is the plural fluid pressure has to be monitored?
Too much or too little would hinder the creation of the negative pressure
What is the pressure of the intrapleural pressure relative to the intra-alveolar pressure?
-4 mm Hg
What happens to intrapleural pressure during inspiration?
It decreases (-4mm Hg at rest) and becomes subatmospheric
What happens to the alveolar pressure relative to the atmospheric pressure?
It drops to be lower than the atmospheric pressure to allow air to be drawn in.
What happens to the intraplueral pressure during expiration?
It increases
What happens to the alveolar pressure relative to the atmospheric pressure?
It is higher than the atmospheric pressure so pressure gradient causes air to be released?
What happens if the intrapleural pressure becomes too positive?
can cause the lung to collapse
