Introduction
Rib cartilage, also called cartilago costalis, is the connection between the ribs and the sternum. Thus the rib cartilages form the last part of the ribs, which are connected to the sternum via the latter. The rib cartilage thus forms a part of the front human thorax. The costal cartilage is a hyaline cartilage, which is both pressure and bending elastic in comparison to the bony ribs and bony sternum. In early adulthood, the cartilage gradually begins to calcify and later also to ossify, which means that the elasticity of the ribcage is increasingly reduced with age.
Anatomy
The rib cartilage represents the connection between the ribs and the sternum. The rib cartilage forms the last 3 – 9 cm of the ribs that are connected to the sternum. The cartilage of the upper six ribs is attached to the sternum by ligaments, the ligamenti sternocostales radiatum.
The ribs six and seven are additionally attached to the lower part of the sternum, the xiphoid process, via a ligament, the ligamentum costoxiphoideum. The rib cartilage forms part of the anterior thorax and is partially palpable from the outside, since the boundaries between the bony ribs and the cartilage tissue are often slightly thickened. Together with the spinal column and the sternum, the ribs form the bony framework of the thorax.
The ribs originate from the spinal column and run along the lung, usually to the sternum. The ribs are divided into so-called “true ribs”, “false ribs” and “free ribs”. In total, humans have twelve ribs.
The “true ribs” are the first seven ribs when viewed from above and are connected to the sternum directly via the costal cartilage. The next three ribs, i.e. ribs eight to ten, are only indirectly connected to the sternum via the so-called Articulatio interchondrales with the rib cartilage of the upper seven ribs. The last two lower ribs have only very short or no rib cartilage and are therefore not connected to the sternum.
The chest surrounds the two lungs and is separated from them only by the pleural cavity. The pleural cavity is a very narrow body cavity that is filled with 5 – 10 milliliters of serous fluid. This reduces the friction between the chest and the lungs. Since the front parts of the ribs are lined with hyaline cartilage, the thorax has slightly elastic properties. These elastic properties are decisive for the freedom of movement of the rib cage.
