Osteology of Vertebral Column

Question 1

Vertebral formula for dogs

Answer 1

C7 T13 L7 S3 Ca 20-23

Question 2

Vertebral formula for cats

Answer 2

C7 T13 L7 S3 Ca 18-21

Question 3

Typical vertebrae structures

Answer 3

Vertebral body
Vertebral arch - pedicle and lamina
Spinous process
Transverse processes and foramen
Articular processes - cranial and caudal
Articular facets (surfaces) - cranial (located dorsally) and caudal (located ventrally)
Vertebral notches - cranial and caudal
Vertebral foramen

Question 4

Structures of C1 (Atlas)

Answer 4

Large transverse processes (wings)
No spinous process, no body (ventral arch in place of body with ventral tubercule)
Caudal and cranial articular fovea
Fovea dentis, located ventrally, articulates with C2
Alar notch - ventral branch of first cervical nerve, first intervertebral vein courses through notch before joining vertebral vein

Question 5

Structures of C2 (Axis)

Answer 5

Prominent spinous process
Cranially located dens that articulates with fovea dentis on C1
Transverse foramen
Cranial articular surface located on cranial extent of body
Caudal articular surface located on arch

Question 6

Structures of C3-C5

Answer 6

Typical vertebral parts
Transverse processes divided (cranial portion located ventrally, caudal portion located dorsally)

Question 7

Structures of C6

Answer 7

Typical vertebral parts
Transverse processes divided (dorsal projection, ventral projection)

Question 8

Structures of C7

Answer 8

Typical vertebral parts
No transverse foramen and transverse process not divided
Has caudal costal fovea for articulation with first rib

Question 9

Structures of thoracic vertebrae

Answer 9

Typical vertebral parts (short transverse processes)
T1-T10: long spinous processes, project caudally
T11: anticlinal vertebra; short vertical spinous process
T12-T13: short spinous processes, project cranially
T1-T9: cranial and caudal costal fovea on their bodies
T10-T13: only have cranial costal fovea on their bodies
T1-T13: costal fovea located on transverse processes

Question 10

Rib articulation

Answer 10

Head of rib 1-10 articulates with caudal costal fovea of preceding vertebra and cranial costal fovea of corresponding thoracic vertebra
Head of rib 11-13 articulates with cranial costal fovea of corresponding thoracic vertebrae
The tubercle of rib 1-13 articulates with costal fovea on the transverse process of the corresponding thoracic vertebra

Question 11

Site of lumbar CSF tap

Answer 11

Performed at the space between L5 and L6 or L6 and L7 vertebrae in dogs and lumbrosacral junction in cats

Question 12

Site of myelography

Answer 12

Performed at the space between L5 and L6 or L6 and L7 vertebrae

Question 13

Structures of the Sacrum

Answer 13

Fused S1-3 vertebrae
Dorsal sacral foramina
Pelvic sacral foramina

Question 14

Caudal/coccygeal vertebrae

Answer 14

Typical vertebral parts
Hemal arch located on Ca4-Ca6

Question 15

Ribs and sternum

Answer 15

13 pairs of ribs in dogs and cats
1-9 sternal
10-12 form costal arch
13 is “floating”
8 sternebrae in dogs and cats

Question 16

Nuchal ligament

Answer 16

Courses between spinous process of axis and spinous process of T1 vertebrae (not in cat)
Continues into supraspinous ligament

Question 17

Supraspinous ligament

Answer 17

Continuation of nuchal ligament
Courses dorsally along spinous processes of T1-Ca3

Question 18

Dorsal longitudinal ligament

Answer 18

Located on dorsal surface of vertebral bodies, ventral to spinal cord
Courses from C2 to sacrum

Question 19

Ventral longitudinal ligament

Answer 19

Located on ventral surface of vertebral bodies
Courses from C2 to sacrum

Question 20

Interspinous ligament

Answer 20

Broad band coursing between spinous processes

Question 21

Intertransverse ligament

Answer 21

Courses between lumbar transverse processes

Question 22

Interarcuate ligament (ligamentum flava, yellow ligament)

Answer 22

Courses between vertebral arches dorsally
Fills interarcuate space