Pectoral girdle

As the shoulder girdle - Latin cingulum membri superioris (human, literally "belt of the upper extremity " ) and cingulate membri thoracici (animals, "Belt said thoracic limb " ) - is known in vertebrates, the bones, the anterior extremities ( in humans the upper, that is, the arms ) to the hull. Together with the pelvic girdle shoulder girdle belongs to the so-called Zonoskelett.

Essentially, there are three bones, but they are not designed in the same manner in all vertebrates:

• Shoulder blade (scapula )
• Collarbone ( clavicle )
• Coracoid ( coracoid )

In teleosts scapula and coracoid are u -shaped connected. The clavicle is Hautverknöcherung as already indicated. In the amphibians the clavicle is missing. In reptiles the clavicle and scapula are often cartilaginous, and there is a interclavicle the the actual collarbone to the sternum ( sternum) connects. Even with limb -less reptiles ( such as snakes) are clavicle and scapula still present in residues. Birds have all three bones of the shoulder girdle. The coracoid is with them the strongest bone (→ bird skeleton).

In most mammals (including humans ), the coracoid is regressed to an extension ( coracoid process ) to the shoulder blade. Only the monotremes have an independent coracoid. Also his collarbone is regressed in most mammals, humans but present and articulated with the manubrium ( part of the sternum ) connected. Except in man and the primates of the most important or even the only bone to connect with the trunk so the scapula, which is connected to the muscular chest ( Synsarkose ).

• Bone