Book One -- The things that sustain and support the entire body, and what braces and attaches them all. [the bones and the ligaments that interconnect them] | Chapter 16 On the Vertebrae of the Thorax

Diversity in the depressions to which the ribs are articulated.

But as the capitula [capita costae] of the ribs vary in that joint, so all the vertebrae do not possess at all the same depressions. Where the first thoracic is joined to the second, the second to the third, and so in succession to the joint of the ninth with the tenth, a certain depression [fovea costalis superior et inferior] (B and C in fig. 1, but more clearly in X and d in fig. 3, ch. 19) is incised on both sides next to the foramina [f. intervertebrale] for the nerves [nn. spinales] (Q, Q in fig. 1, ch. 14). This depression is common to the bodies of both vertebral bodies that are connected to each other, and is incised partly into the body of the vertebra above and partly into the one below, though its larger portion extends more to the lower vertebra. 16 This depression is coated with cartilage, 17 and is formed nearly in the shape of an obtuse angle, much as the capitulum [caput costae] of the ribs (L in fig. 4, ch. 19) entering this depression bulges in the manner of an obtuse angle, as we shall show in our discussion of the ribs. The first thoracic vertebra has the following property along with the eleventh and twelfth: a special depression on each side not shared with other vertebrae, 18 carved in its body alone (look for these in E and F, fig. 4). 19 Near the upper surface of the first thoracic vertebra, a round, quite deep depression [fovea costalis] is hollowed out on each side and lined with cartilage; to this is articulated the base [collum costae] of the first thoracic rib by means of a round capitulum. At the bottom of this depression, another quite deep one is seen, rough and uneven, filled with certain foramina and not covered with cartilage; from this comes an extremely strong ligament [l. costotransversarium] that powerfully binds the rib into its socket. Similarly, the depression 20 carved in the twelfth vertebra for the twelfth rib possesses another deep depression in its lower surface, also rough, but less so than the just mentioned depression of the first vertebra; this one is hollowed out for the ligament [l. costotransversarium laterale] attaching the twelfth rib more firmly to the vertebra.



Book One -- The things that sustain and support the entire body, and what braces and attaches them all. [the bones and the ligaments that interconnect them] | Chapter 16 On the Vertebrae of the Thorax