Costal cartilages are flexible tissues that connect the ribs to the sternum (breastbone) in the human body. They play a crucial role in forming the rib cage, allowing it to expand and contract during breathing. This flexibility helps protect vital organs in the chest, such as the heart and lungs. These cartilages are made of hyaline cartilage, which is smooth and resilient. In total, there are seven pairs of true costal cartilages that attach directly to the sternum, along with several pairs of false costal cartilages that connect indirectly. This structure contributes to the overall strength and flexibility of the thoracic skeleton.