brystkassens

Brystkassen, or the thoracic cage, is the protective bony and cartilaginous framework that forms the front, sides, and top of the thorax. It encloses the thoracic cavity, housing the heart and lungs and providing attachment points for muscles involved in respiration and upper limb movement.

The skeleton of the brystkassen consists of 12 pairs of ribs, their costal cartilages, the sternum (comprising the manubrium, body, and xiphoid process), and the thoracic portion of the vertebral column. The ribs articulate with the vertebrae posteriorly and with the sternum anteriorly either directly or via costal cartilages. The diaphragm forms the inferior boundary, and intercostal muscles between the ribs aid in expansion and contraction during breathing. The clavicles and scapulae lie adjacent to the brystkassen and contribute to shoulder movement but are not themselves part of the rib cage.

Functionally, the brystkassen protects vital organs such as the heart, lungs, and major vessels. It also provides a rigid yet movable enclosure that can expand during inhalation to increase the volume of the thoracic cavity, aiding respiration in conjunction with the diaphragm and intercostal muscles. The cage serves as an anchor for muscles of the upper body and trunk.

Clinical relevance includes rib fractures from trauma, which can impair ventilation, and deformities such as pectus excavatum (funnel chest) or pectus carinatum (pigeon chest) that alter the shape of the sternum. In some cases, surgical access to the heart or great vessels involves deliberate separation of parts of the brystkassen (sternotomy).