Ribbenene

Ribbenene are the bones that form the thoracic cage in humans and most mammals. They protect the organs of the chest, such as the heart and lungs, support the upper body, and assist in breathing by allowing the chest to expand and contract. In adults, there are typically 24 ribs, arranged in 12 pairs.

Anatomy: Each rib consists of a curved shaft with a head that articulates with the bodies of the thoracic vertebrae, a neck, and a tubercle that articulates with the transverse process of the same-numbered vertebra. The costal cartilage extends anteriorly to connect the rib to the sternum (or to the cartilage of the rib above). Ribs 1–7 are true ribs with direct sternal attachment; ribs 8–10 are false ribs that join the cartilage of the rib above; and ribs 11–12 are floating ribs with no anterior attachment.

Joints and connections: The rib head articulates at the costovertebral joints with adjacent vertebrae, the tubercle at the costotransverse joints, and the sternum is connected by costal cartilage to form the front of the thoracic cage. The upper ribs contribute to the thoracic inlet and increase chest volume during inspiration.

Variations: Some individuals have anatomical variants, including cervical ribs or supernumerary ribs. There is natural variation in rib length, curvature, and articulation among people.

Clinical relevance: Rib injuries, including fractures, are common after blunt trauma and can impair respiration. Knowledge of ribbenene anatomy is important in imaging and surgical procedures involving the chest.