The thoracic skeleton is a part of the human skeleton that includes the rib cage, which protects vital organs such as the heart and lungs. It consists of 12 pairs of ribs, the sternum, and the thoracic vertebrae. This structure provides support and stability to the upper body while allowing for flexibility during breathing. The thoracic skeleton plays a crucial role in respiration. When the diaphragm and intercostal muscles contract, the rib cage expands, creating a vacuum that draws air into the lungs. This process is essential for oxygen intake and carbon dioxide removal, vital for maintaining life.