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Respiratory Part 3
Question | Answer |
---|---|
When pressure inside the IAS is greater than the pressure inside the IPS what does the lungs do? | Expand. As IPP become more negative the lungs will expand |
What happens if the liquid seal between the lungs and wall is broken? | Lungs will collapse and the chest wall will move out. |
Describe the pressure of the fluid in the intrapleural space | The pressure of the fluid is negative because of the opposing tendencies of the lung and the thorax. The fluid in the IPS is subjected to a distending force and its pressure is negative. |
When erect where is the pressure variation most dramatic? | Apex and base. Weight of lungs causes it to pull away from the apex and rest on the diaphragm making IPP more negative at the apex (-10) and less negative at the base (-2) |
What is IPP a measure of? | The elasticity of the lungs at the beginning and end of inspiration |
Sequence of events of Respiratory cycle | Respiratory muscles contract, enlarges the thorax, IPP becomes more negative, Lungs expand, IAP becomes negative, Air movement into the lungs |
Is the IPP positive during normal respiratory cycle? | No. It solely fluctuates in the negative range but may become positive under special circumstances. |
Name one factor that would cause the IPP become + | During positive pressure respiration, the outward movement of the lungs "compresses" the IPS and raises its pressure. Anytime inspiration is accompanied by blowing up the lungs IPP becomes +. |
Name another factor that causes IPP to become + | During active expiration, the respiratory muscles "compress" the IPS so IPP becomes + |
Pneumothorax | Air in a IPS, liquid seal breaks and lung collapse. Trauma: stab wound, volume trauma: diver who comes up to fast w/o exhaling. Spontaneous: Rupture of alveolus, common at apex. Tension: Air continues to come in |