Question

In mouth-to-mask ventilation, the stomach is likely to be distended if too great a force is used to inflate the lungs. Lung ventilation may become more difficult because stomach inflation ________.

1) increases the pressure in the thoracic cavity
2) decreases the pressure in the thoracic cavity
3) compresses the diaphragm
4) obstructs the airway

Answer 1

Stomach inflation in mouth-to-mask ventilation compresses the diaphragm and complicates lung ventilation by affecting the thoracic cavity dynamics essential for proper breathing, as described by Boyle's Law.

Step-by-step explanation:

In mouth-to-mask ventilation, the stomach inflation can complicate lung ventilation because it compresses the diaphragm. When you use too much force to inflate the lungs, excess air can enter the stomach, causing it to distend. This distention pushes up against the diaphragm, impeding its ability to contract and relax as needed for proper lung ventilation. As the diaphragm is compressed by the inflated stomach, the thoracic cavity's space is diminished, affecting the volume and pressure dynamics essential for breathing.

Thoracic cavity dynamics are vital because they determine lung function through the balance of pressures and volumes within the chest area. The chest wall and diaphragm must work in harmony to maintain the negative pressure that aids lung expansion during inhalation, as outlined by Boyle's Law. Any factor, like stomach distention, which impairs this dynamic can hinder the breathing process.