Key to the Eleven Figures and Characters of the Fifteenth Chapter
The first figure of the present chapter shows part of the occipital bone free from other bones, and is seen here in the outer surface of the base of the skull.
The second sets forth the first vertebra [atlas] of the neck, shown in its anterior and superior aspect.
The third presents to view a superior and posterior image of the first cervical vertebra.
The fourth exhibits the first cervical vertebra drawn in its inferior and posterior aspect.
The fifth demonstrates the anterior face of the second cervical vertebra [axis]. 1
The sixth represents the posterior face of the second cervical vertebra.
The seventh offers to view the second cervical vertebra in its inferior face.
The eighth illustrates the anterior and superior face of the third cervical vertebra.
The ninth delineates the posterior and superior face of the third cervical vertebra. Because the lower surface of this cervical vertebra resembles the lower surface of the second vertebra, we do not include it here, to avoid setting out too great a mass of illustrations before the present chapter. For this reason as well we have not individually depicted the remaining cervical vertebrae after the third, especially as their description can be readily inferred from the figures of the three upper vertebrae.
In the tenth is seen the structure of the first three cervical vertebrae depicted in the anterior part.
In the eleventh is shown the assembly of the first three cervical vertebrae from a posterior view.
|A in figure 1||Foramen [f. magnum] cut out in the occipital bone for the dorsal medulla [medulla spinalis].|
|B 1||Right capitulum [condylus] of the occipital bone, which is articulated with the first cervical vertebra.|
|C, D, E, F 1||The left capitulum is marked C, D, E, and F. C and D show the longitude or line by which we measure length in describing these capitula. E shows the inner side of the capitulum, which is depressed lower than the outer, marked F, or does not stand out as high.|
|G 1||Anterior region [pars basilaris] of the foramen that transmits the dorsal medulla, which is rough and uneven for the insertion of a certain rounded ligament. 2|
|H 1||Depression [fossa condylaris] 3 cut in the area behind each capitulum of the occipital bone, providing a path for the first pair of nerves of the dorsal medulla.|
|I 2 , 3 , 4||Foramen [f. vertebrale] carved in the first cervical vertebra for transmitting the dorsal medulla.|
|K 2 , 3||Here the body of the first vertebra is carved out [arcus anterior atlantis] to accept the tooth [dens axis] of the second vertebra, which will be labeled G. 4|
|L 3 , 4||Depression [fovea dentis] cut in the posterior part of the body of the first vertebra, covered with cartilage.|
|M 2 , 10||Process and tubercule [t. anterius] protruding on the anterior surface of the body of the first cervical vertebra.|
|N 2 , 3 , 10 , 11||Right depression [massa lateralis atlantis, facies articularis superior] of the first vertebra, by which the right capitulum [condylus] of the occipital bone is received.|
|O, P, Q, R[ 2 , 10 ]||I have labeled the left depression in the second and tenth figures with these letters: marking the longitude O and P, and the inner side Q, which is much lower than the outer side labeled R.|
|S 2 , 3 , 4 , 10 , 11||Right transverse process of the first cervical vertebra. We have not labeled the left one because the structure of each is the same. 5|
|T[ 2 , 11 ]||In the same way, we have marked its foramen T [f. transversum] only on the left side of the second and eleventh figure.|
|V 3 , 11||The depression [sulcus arteriae vertebralis] that makes a foramen jointly with the depression marked H in the occipital bone is marked only on the right side. Through this foramen [f. intervertebrale] passes the first pair of nerves of the dorsal medulla.|
|X 3 , 4 , 11||Here the first cervical vertebra is lacking a posterior process [p. spinosus], 6 and there is seen only a short, sharp tubercule [t. posterius] projecting like a line, at whose side this place is rough.|
|Y 4||The right depression [massa lateralis atlantis, facies articularis inferior] of the first cervical vertebra, receiving the right protuberance [facies articularis superior] of the second vertebra marked c.|
|a, b[ 4 ]||We have marked the left depression a and b; a marks its inner side, b its outer.|
|c 5 , 6||Right protuberance or significantly lowered capitulum [processus articularis superior] of the second vertebra, which enters the previously mentioned depression in the first vertebra marked Y.|
|d, e, f[ 5 , 6 ]||These mark the left capitulum [facies articularis superior]. d identifies its higher, inner side, e its outer and more depressed side, f the part of the capitulum which extends to the posterior as if beyond the circumference of a circle.|
|G 7 , 10 , 11||Process of the second cervical vertebra, which we shall call the dens [dens axis] 7 because it resembles a tooth, and which is also visible in the fifth as well as the tenth and eleventh figure, labeled G. In the fifth and sixth figure it is marked by several figures, each denoting|
|g[ 5 ], h[ 6 ]||In the fifth, g marks its tubercule [apex dentis] covered by cartilage; in the sixth, h marks the posterior surface of the dens, which is thicker and swells more to the posterior than the root of the dens.|
|i[ 5 , 6 ]||Depression [facies articularis posterior] on which the transverse ligament is wrapped which restrains and contains the dens in the first vertebra.|
|k, l[ 5 , 6 ]||Depression incised on each side of the beginning or root of the dens, transmitting the very small branches of the anterior nerve of the second pair of nerves of the dorsal medulla. 8|
|m[ 11 ], n[ 5 ]||The foramen formed from this depression (k, l) and the one in the first vertebra is marked m in the eleventh figure. In the fifth figure n marks the point of the dens. 9|
|o 3 , 11||The rough surface (tubercle for transverse ligament) of the right side between the upper depression [facies articularis superior] of the first vertebra, marked N, and the lower [facies articularis inferior], marked Y, where the foramen is seen that does not go through.|
|p 6||Depression [pediculus arcus vertebrae] of the right side, hollowed out on the posterior side of the right process, marked c [facies articularis superior], of the second vertebra; it forms the common foramen or route by which the second pair of nerves of the dorsal medulla passes to the posterior.|
|q[ 4 ]||On the left side of the fourth figure you see a q, marking this depression [arcus posterior atlantis, sulcus arteriae vertebralis] of the first cervical vertebra.|
|r[ 10 , 11 ]||On the right side in the tenth and eleventh figures I have put an r, signifying as well as possible the same path of the nerves [nn. cervicales II] on the other side.|
|s 5 , 6 , 7||Posterior process or spine of the second cervical vertebra, which is also visible in its upper part in the tenth and eleventh figures, and in its lower part in the seventh. 10|
|t 9||Spine of the third cervical vertebra, 11 also shown in the eleventh figure. The tips of this spine are labeled c and ϖ in the eighth figure, and the spine itself is also marked there with the number eleven. 12|
|u 5 , 6 , 7||Right transverse process of the second cervical vertebra. The left process is unlabeled in those figures, and the process of either side will readily be recognized in the tenth and eleventh figures. 13|
|x 5 , 6 , 7||Foramen of the transverse process of the second cervical vertebra.|
|y, z 9 , 10||Transverse process of the left side of the third cervical vertebra; y 14 marks the inner portion [tuberculum posterius], z the outer [t. anterius], 15 and in the eighth figure 7 and 8 mark the transverse process of the right side while 9 and 10 mark the process of the left side.|
|a 8 , 9||Foramen [f. transversarium] of the transverse process of the third cervical vertebra.|
|b 6 , 7 , 11||Right descending process [p. articularis inferior] of the second vertebra, the shape of whose depression [facet] the seventh figure illustrates.|
|g 9 , 11||Right descending process of the third cervical vertebra; g marks its [superior] posterior surface in the ninth and eleventh figures. Its inferior surface or depression corresponds to the hollow [facet] marked b in the seventh figure. 16|
|d 9 , 11||Right ascending process [p. articularis superior] of the third cervical vertebra; the ninth figure shows its tuberosity [facet], 17 and the eighth marks the protuberances of the ascending process of either side with the numbers 3 and 4.|
|e 5 , 6 , 7 , 10 18||Place where the body of the second vertebra extends downward.|
|z 9||Place where the body of the third vertebra is taken downward.|
|h 9||Upper depressed place [facies intervertebralis corporis vertebrae] of the third cervical vertebra; h marks the depression, while q and k mark the rising process on each side [uncus corporis]. These processes are seen in the eighth figure, marked by the numbers 1 and 2. 19|
|l m n 10||Anterior surface of the body [corpus axis] of the second vertebra, where l marks the swelling tuberosity, while m and n mark each of the lowered sides of the protuberance.|
|1, 2, 3, etc.[ 8 ]||The numbers appearing on the eighth figure mark the number of processes of the third cervical vertebra. 1 and 2 mark two protruding parts on the upper surface of the vertebral body [uncus corporis], 3 and 4 the two ascending processes [p. articularis superior], 5 and 6 the two descending processes [p. articularis inferior], 20 7, 8, 9, and 10 the transverse processes [tuberculum anterius, t. posterius].|
|c, ϖ, r [ 8 ]||Number 11 marks the spine, whose points 21 are labeled c and ϖ. The inferior part of this vertebra is labeled r.|
|j 8 , 9||Depression [lamina arcus vertebrae] that forms the lower part of the foramen [f. intervertebrale] by which the third pair leaves the dorsal medulla.|
|t, t 7||Depression that forms the upper part of the foramen just mentioned.|