The lumbar nerves are the five spinal nerves emerging from the lumbar vertebrae. The cervical spinal nerves emerge from above the cervical vertebrae. The thoracic nerves are the twelve spinal nerves emerging from the thoracic vertebrae. There are seven cervical vertebrae, twelve thoracic vertebrae and five lumbar vertebrae. There are seven cervical vertebrae (but eight cervical spinal nerves), designated C1 through C7. All ribs are attached posteriorly to the thoracic vertebrae. The sacrum consisted of three to ten sacral vertebrae. There are seven cervical vertebrae, twelve thoracic vertebrae, and five lumbar vertebrae. Ribs are found exclusively on the thoracic vertebrae. The third and fourth sacral vertebrae are keeled. The bonobo differs by having four lumbar vertebrae. The accident left him with two fractured cervical vertebrae in his neck. They travel upward through transverse foramina which are spaces in the cervical vertebrae. The number of sacral vertebrae varies slightly. Below the caudal vertebrae is the chevron bone.