Thoracic vertebrae

The thoracic vertebrae form the thoracic spine, a slightly dorsoconvex bony rod, characterized by its limited flexibility. The main differences between other vertebrae (cervical and lumbar) are:

• Articulations with the ribs that correspond in number
• Short bodies with flattened extremities
• Short articular processes
• Vertebral arches closely fitting (no real interarcual spaces)
• Long spinous process
• Costal facets on the transverse processes and cranial and caudal costal fovea on the extremities of the vertebral bodies

The number of thoracic vertebrae differ between species. Here are different vertebral formulae:

• Dogs: C7 T13 L7 S3 Cd20
• Horses: C7 T18 L6 S5 Cd15-21
• Bovine: C7 T13 L6 S5 Cd18-20
• Ovine: C7 T13 L6-7 S4 Cd16-20
• Pigs: C7 T14-15 L6 S4 Cd20-23