Rib

As rib (lat. Costa, plural costae, adjective costal AltGr. Πλευρά, pleura ) is called the rod-shaped bones of the thorax, the dorsal side are hinged to the thoracic spine. A normal variant, for example, the fork rib.

Construction

Each rib consists of a spine- side rib bone (Os costale ) and in mammals addition of a cartilaginous portion, the rib cartilage ( costal cartilage ). The gap between two consecutive ridges is referred to as intercostal (ICR, intercostal space, space intercostal ). This space is filled externi and interni by the Musculi intercostal.

The ribs are articulated with the spine in conjunction. The heads of the ribs will touch two consecutive vertebrae, but in humans, the 1st, 11th and 12th ribs articulate only with each equinumerous thoracic vertebrae. The connection with the vertebral bodies is ripping head (caput costae ), whose joint surface ( articular facies capitis costae ) in the ribs - in humans only the 10th rib to the second - is divided into two parts. Below the rib capitulum the rib to rib neck tapers ( collum costae ). On ribs neck is the hump ribs ( costal tubercle ), which also has a joint surface ( articular facies tuberculi costae ) which forms a joint with the articular surface ( fovea costal processus transversi ) of equinumerous transverse process.

The subsequent towards the breastbone part is the ribbed body (corpus costae ). He contributes to the caudal inside a groove ( sulcus costae ), in the run the intercostal nerves and blood vessels. The ribbed body goes through in the Rippenfuge in the rib cartilage ( costal cartilage ). The latter is connected with the " true ribs " with the sternum. In " wrong ribs " this is done only on the cartilage of the "true ribs " six and seven. The floating ribs are not connected to the sternum.

Classification and number

The number of ribs corresponds to the species-specific number of thoracic vertebrae. The upper (with animals front ) fins are connected in mammals via the costal cartilage directly with the sternum ( sternum). These are called sternal ribs. The lower ( rear ) fins are attached to the cartilaginous rib cage ( costal arch ), they are called aster signals ribs. The last ribs are free ( fluctuantes costae ) in the abdominal wall as a so-called " meat " or " fleeing ribs " ( the dog, the cat and man ) occur.

Man has twelve pairs of ribs, the upper seven ribs sternal, the eighth to tenth aster signals and the two bottom end freely in the muscles. The sternal pairs of ribs ( 1-7 ) are also referred to as "real ribs " ( verae costae ), the pairs of ribs 8-12 as "false ribs " ( costae spuriae ). As variety may occur on the seventh cervical vertebra, a cervical rib.

Domestic Dog, Domestic Cat, Domestic Cattle, Domestic goat and domestic sheep usually have 13 pairs of ribs. The domestic pig has 14 to 17 pairs of ribs, the domestic horse 18