What part of the skeleton protects the heart and lungs?

The rib cage is the part of the skeleton that provides critical protection for the heart and lungs. It comprises the ribs, sternum, and thoracic vertebrae, forming a sturdy enclosure that safeguards these vital organs from external trauma. The ribs are attached to the thoracic vertebrae at the back and curve around to connect to the sternum at the front, creating a protective cavity known as the thoracic cavity. This structure not only protects the heart and lungs but also assists with respiration by allowing the chest to expand and contract during breathing. The other options, such as the skull and spine, serve protective functions for the brain and spinal cord, respectively, while the pelvis supports the lower organs and plays a role in the reproductive system, but none of these provide direct protection to the thoracic organs.