Bones of the Spine. 



69 



Processus spinosus 



Processus transversus 



Processus articularis superior 

 Fovea costalis superior 



Fovea costalis 

 transversalis 



Processus 



articularis 



superior 



Fovea costalis inferior 

 Incisura vertebralis inferior 



Processus articularis inferior 



Processus spinosus 



86 and 87. Sixth thoracic vertebra, vertebra thoracalis VI, 



From above. 



From the right. 



The twelve vertebrae thoracales (thoracic vertebrae, 0. T. dorsal vertebrae) (see also 

 Figs. 88, 106 and 107) possess broad bodies. The connecting surfaces of the bodies are flat 

 and on the upper and lower vertebrae are described as bean-shaped, on the middle vertebrae 

 as more heart-shaped. The foramen vertebrate is narrow and rounded. The processus 

 articulares stand nearly frontally, their fades articulares are slightly curved and form parts 

 of the mantle of a cylinder, the axis of which is situated in front of the body; the facies 

 articulares superiores look backward, the facies articulares inferiores forward. The processus 

 transfer si arise between the processus articulares and are very powerful ; they are, below more 

 than above, directed obliquely backward and lateralward. On the anterior surface of their 

 lateral extremity they present a small fossa covered with cartilage, the fovea costalis trans- 

 versalis (0. T. facet for tubercle of rib) for articulation with the tuberculum costae; they are 

 absent from the eleventh and twelfth , sometimes also from 'the tenth vertebra (see Fig. 88). 

 The processus spinosi are long, triangular, apical and directed more or less markedly down- 

 ward; the middle ones cover one another like tiles of a roof (see Figs. 106 and 107). The 

 small articular surfaces which lie on the lateral surfaces of the bodies of the vertebrae, just 

 in front of the roots of the vertebral arches, are special peculiarities of the thoracic vertebrae. 

 On the nine upper vertebrae two of these are present on each bone, one larger at the upper 

 margin, fovea costalis superior (0. T. demifacet for head of rib) and one smaller on the lower 

 margin, fovea costalis inferior ; each fovea costalis inferior forms with the fovea costalis 

 superior of the next vertebra below and with the intervertebral disc lying between them the 

 articular surface for one capitulum costae. On the tenth to the twelfth vertebra (see Fig. 88) 

 there is only one fovea costalis; on the tenth it lies on the upper margin, on the eleventh 

 and twelfth vertebra in the middle of the lateral surface. 



