Axial Skeleton and Muscles Flashcards
Cervical vertebrae
Seven. Atlas, axis. 3-7 have a ventral crest and gradually increasing spinous processes.
Thoracic vertebrae
Thirteen. All have prominent spines. The first 10 have tall caudally inclining spines. The 11th is the anticlinal vertebra. The 12th and 13th have spines that incline cranially.
Lumbar vertebrae
Seven. All have prominent but blunt spinous processes. Large transverse processes directed cranially and ventrolaterally.
Sacral vertebrae
Three, fused into a single bone. Body of the first segment is larger than the combined bodies of the next two segments.
Caudal vertebrae
Twenty. Lose distinctive features as they move caudally.
Vertebral body
ventral side of the vertebra. constricted centrally. Dogs: cranial extremity convex, caudal extremity concave.
Vertebral arch
dorsal side of the vertebra. Two pedicles (basal) and two laminae (dorsal)
Nucleus pulposus
Soft center of the intervertebral disc.
Anulus fibrosus
Concentric layers of dense tissue, the outer layer of the intervertebral disc.
Vertebral foramen
Main canal formed by the vertebral body and vertebral arch.
Vertebral canal
All vertebral foramina join together to form this.
Cranial vertebral notches
shallow notches formed by the vertebral arch pedicles.
Caudal vertebral notches
Deeper notches than the cranial, formed by the vertebral arch pedicles.
Intervertebral foramina
Spaces that the vertebral notches form with the bodies of adjacent vertebrae, along with the intervening fibrocartilage. Spinal nerves and blood vessels pass through these points.
Spinous process
dorsally located vertebral
Transverse process
lateral vertebral processes from the region where the arch joins the vertebral body.
Articular processes
Cranial and caudal on each vertebra. At the junction of the pedicle and the lamina on the vertebral arch. Cranial articulating surfaces point medially or dorsally, caudal surfaces are ventrally or laterally.
Atlas
1st cervical vertebra. Articulates with the skull cranially. Lacks a spinous process and has a reduced vertebral body.
Wings of the Atlas
Origin of the omotransversarius. Thick shelflike transverse processes of the atlas, which have the transverse foramina running obliquely dorsal/ventral.
Cranial articular fovae of the atlas
On the atlas, fovae that articulate with the occipital condyles of the skull to form the atlanto-occipital joint.
Atlanto-occipital joint
Between the atlas and the occipital condyles of the skull. Main movement is flexion and extension.
Caudal articular fovae of the atlas
shallow glenoid cavities that articulate with the axis.
Atlantoaxial joint
Rotatory movement occurs between the atlas and the axis.
Fovea dentis
Concave part of the dorsal surface of the vertebral body on which the dens of the axis rests.