floating rib

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floating rib

A false rib whose anterior end is unattached. The lowest two pairs of human ribs are floating ribs.


(rib) [AS. ribb]
Enlarge picture
RIB CAGE: Anterior view
One of a series of 12 pairs of narrow, curved bones extending laterally and anteriorly from the sides of the thoracic vertebrae and forming a part of the skeletal thorax. With the exception of the vertebral ribs, they are connected to the sternum by costal cartilages. See: illustration

asternal rib

False rib.

bicipital rib

An irregular condition resulting from the fusion of two ribs, usually involving the first rib.

cervical rib

A supernumerary rib sometimes developing in connection with a cervical vertebra, usually the lowest.

false rib

One of the lower ribs (8, 9, and 10) that do not join the sternum directly. Their cartilage connects to the cartilage of the seventh rib. The variation in the anatomy of the lower ribs may be considerable (i.e., there may be only two false ribs).
Synonym: vertebrochondral rib

floating rib

Vertebral rib.

lumbar rib

A rudimentary rib that develops in relation to a lumbar vertebra.

slipping rib

A rib in which the costal cartilage dislocates repeatedly.

spring fracture of rib

Outward displacement of the end of a broken rib, seen on x-ray examination of ribs that are broken by compression rather than by direct blows to the chest.

sternovertebral rib

True rib.

true rib

Any of ribs 1–7, which articulate directly with the sternum. Synonym: sternovertebral rib

vertebral rib

Any of ribs 1–7, which articulate directly with the sternum.

vertebrochondral rib

False rib.

vertebrocostal rib

Any of the three false ribs on each side.

floating rib

One of the two lowest pairs of short ribs that have no attachment at the front to the breastbone or the COSTAL CARTILAGES but end among the abdominal muscles.


any one of the paired, curved, cylindrical bones, extending from the thoracic vertebrae to the ventral aspect of the trunk, forming the major part of the thoracic skeleton, and consisting of a dorsal bony part and a ventral cartilaginous part that may or may not articulate with the sternum. Typically 13 pairs in the dog, cat and ruminants, 18 pairs in horses and 14 or 15 pairs in the pig. Called also costa. See Table 10.

abdominal r's, asternal r's
a rib whose ventral end does not meet the sternum. See also false ribs (below).
cervical rib
a supernumerary rib arising from a cervical vertebra.
rib contractor
a strongly built device for pulling ribs together following retraction for surgical access to the thoracic cavity.
false r's
the caudal ribs, not attached directly to the sternum but are attached to each other's sternal cartilage to form the costal arch.
floating rib
a rib whose distal extremity is unattached to an adjacent rib or the sternum.
rib retractor
heavy duty surgical instrument for separating ribs to allow surgeon better access to thoracic contents. See finochietto rib spreader.
slipping rib
one whose attaching cartilage is repeatedly dislocated.
sternal rib
true ribs articulating with the sternum.
true r's
the ribs attached to both vertebrae and sternum.
vertebral r's
floating ribs.
vertebrocostal r's
the false ribs that contribute to the costal arch.
vertebrosternal r's
true ribs.