Final answer:
The thoracic cage forms the skeleton of the chest and protects the lungs and the heart.
Step-by-step explanation:
The thoracic cage forms the skeleton of the chest and protects the lungs and the heart. It consists of the ribs, sternum, thoracic vertebrae, and costal cartilages. The ribs and sternum enclose and protect the thoracic cavity where the heart and lungs are located. Changes in the volume of the thorax enabled breathing.