Why does the diaphragm play a significant role in a child's breathing compared to an adult?

The diaphragm is crucial to a child’s breathing because, in infants and young children, the intercostal muscles—the muscles located between the ribs that assist in breathing—are not as fully developed as in adults. This leads to dependence on the diaphragm for respiratory function. In children, the diaphragm serves as the primary muscle for breathing, making it especially significant for their ventilation. The ability of the diaphragm to effectively contract and expand allows children to maximize their lung capacity, even when their accessory muscles are not as developed.

In adults, the intercostal muscles are more developed and provide additional support during breathing, allowing for a more robust respiratory effort. However, in a child, who lacks this muscle development, the diaphragm compensates, hence its critical role in the respiratory process for pediatric patients. This makes understanding the mechanics of a child's breathing essential, particularly in emergency situations where respiratory distress is a concern.