Certain chest deformities prevent normal expansion of the chest. Explain why this makes ventilation difficult in terms of pressure and volume.

The lungs work by expanding and going back to their original size when you inhale and exhale. The rib cage also expands so the lungs can have more air inside and expand. Due to deformities, the rib cage might not expand and/or the diaphragm might not lower itself, which might lead to pressuring the lungs not to expand and having a lower volume of air inside. This leads to breathing difficulties.