Features of the musculoskeletal system of birds in connection with flight.

The skeleton and muscles of birds have structural features, thanks to which birds fly. The tubular bones are hollow inside – this gives lightness to the skeleton, some bones are completely fused (cranial, humerus) – this gives strength. Each rib of the skeleton connects two parts of the spine, which allows you to coordinate the movement of the sternum during flight and makes breathing easier. The strong pectoral muscles, which are attached to the keel, help to raise and lower the wings. Only flying birds have such an outgrowth of the sternum. The muscles are developed to varying degrees: the pectorals are strong, the muscles of the spine are weak. There is little connective tissue in the muscles, and the diaphragm is poorly expressed.