Ribs of limbs are a pair of bone structures in the lower part of human chest, also known as ribs. Everyone usually has 12 pairs of ribs, which are connected to the front of the sternum through cartilage and to the back of the body through the spine of the back. The main function of ribs in limbs is to protect internal organs, such as the heart and lungs, and provide a structure to support and protect the chest. The first seven pairs of ribs are directly connected with the sternum, which are called true ribs; The lower three pairs of ribs are indirectly connected with the sternum through cartilage, which is called false ribs; The last two pairs of ribs are not connected to the sternum, which are called floating ribs.