Costal cartilage
Cartilago costalis
Definition
The costal cartilage is the cartilaginous portion of the ribs. It corresponds to the ventral part of the rib, extending the bony portion in the form of cylindrical cartilage. Its diameter is smaller than that of the bony portion and it can be calcified in adult dogs.
It has a cranial inclination near the costochondral joint, which is particularly pronounced in the first and twelfth pairs of ribs.
Variation:
In dogs and cats, the costal cartilage of the first pair of ribs articulates directly with the manubrium, while those of the second to seventh pairs articulate with the intersternal cartilages. The cartilages of the eighth and ninth pairs join the cartilage located between the seventh sternebra and the xiphoid process. The costal cartilages of the tenth, eleventh, and twelfth ribs are long, thin, and joined together by connective tissue to form the costal arch.
The costal cartilage of the thirteenth rib is shorter and does not articulate: it ends in the flank musculature.
References
Evans HE, de Lahunta A. Miller’s Anatomy of the Dog. 5th ed. St. Louis: Elsevier; 2013. Chapter 4, The skeleton; p. 80–157.
