Which type of bone contains air spaces?

Pneumatic bones are characterized by the presence of air spaces or cavities within their structure. These bones are often lighter than solid bones due to the reduction of dense material, which allows them to effectively reduce the overall weight of the skeletal system. A common example of pneumatic bones is found in birds, where the air-filled spaces contribute to a lighter body, facilitating flight.

In contrast, long bones, irregular bones, and flat bones do not typically feature these air-filled cavities. Long bones, such as the femur or humerus, are primarily composed of dense bone tissue and are designed for support and movement. Irregular bones, including the vertebrae and certain skull bones, have complex shapes tailored for specific functions but lack the pneumatic quality. Flat bones, like the sternum and scapula, serve protective roles and muscle attachment but also do not possess air-filled spaces. Thus, pneumatic bones stand out due to their unique structure and functional advantages.