Axial Skeleton

Question 1

What is the vertebral formula for the dog?

Answer 1

C7, T13, L7, S3, Ca20-24

Question 2

What is the vertebral formula for the horse?

Answer 2

7, 18, 6, 5, 15-21

Question 3

What are the 5 basic parts of a typical vertebra?

Answer 3

Vertebral foramen
Body
Intervertebral foramen (where spinal cord goes through)
Intervertebral discs
Vertebral arch

Question 4

What are the 7 processes of the vertebral arch?

Answer 4

Spine/spinous process
(two) transverse processes
(four) articular processes; 2 cranial + 2 caudal

Question 5

What are the features/structures of bone C1?

Answer 5

Supports the head (“atlas”); has no body or spine.

Has a ventral arch, wings, and transverse foramen.

Articulates with the occipital condyles to form the atlanto-occipital joint.

Question 6

What are the features/structures of bone C2?

Answer 6

Known as the “axis”

Large ridge-like spinous process

Has dens: peg-like cranial process, forming a pivot joint with the atlas.

Question 7

What are the features/structures of bone C6?

Answer 7

Transverse process has a large wide ventral projection (looks like a sled).

Question 8

What are the features/structures of bone C7?

Answer 8

Has a higher spinous process

No transverse foramen

Articular facet of its caudal surface for the head of the 1st rib

Question 9

What are the features/structures of the General Thoracic Vertebrae?

Answer 9

Articular/costal facets (attaches to the ribs)

Anticlinal vertebra: has the most vertically orientated spine. All spines cranial to it are inclined caudally, all spines caudal to it are inclined cranially.

T11-T13 have only one pair of costal fovea

Transverse processes are short

Mammillary processes (four)

Accessory processes

Question 10

What are the features/structures of the General Lumbar Vertebrae?

Answer 10

Vertebrae of the lower back (7 total)

Has larger, long, plate-like transverse processes that direct cranially

No costal facets

Accessory processes (caudal end) present from mid-thoracic to the
lumbar vertebra

Mammillary processes (associated with the cranial articular processes)

Question 11

What are the features/structures of the Sacrum?

Answer 11

Formed from the fused sacral vertebrae

Articulates with the hip bones to form the sacroiliac joint

Dorsal/ventral sacral foramina

Has wings and a median sacral crest (fused spinous processes in ruminants)

Spinous processes (unfused processes in carnivores and horses)

Question 12

Which vertebra is the anticlinal vertebra in the dog?

Answer 12

Vertebra T11

Question 13

What are true ribs?

Answer 13

ribs that articulate directly by their costal cartilage with the sternum

Question 14

What are false ribs?

Answer 14

ribs that do not articulate with the sternum

Question 15

What are floating ribs?

Answer 15

in dogs, they do not form the costal arch.

They are the last pair of ribs in the dog’s rib cage that are attached to the spine but do not extend all the way round to the sternum.

Question 16

What are the manubrium and the xiphoid process?

Answer 16

Manubrium - most cranial part, 1st sternebrae

Xiphoid process - rear end of sternum, last sternebrae

Question 17

Which species of animal does not have a nuchal ligament?

Answer 17

Nuchal ligaments are absent in felines/cats.

Question 18

What are the 2 parts of the nuchal ligament in the horse/ox?

Answer 18

1. Funicular (“cord”) part
2. Lamellar (“sheet”) part

Question 19

What are the 2 parts of the intervertebral disk and their features?

Answer 19

Annulus fibrosus
- thin dorsally and thick ventrally

Nucleus pulposus
- semi-fluid
- functions to absorb shock

Question 20

What are the two types of costovertebral joints?

Answer 20

1. Head of rib with the caudal and cranial costal facets of adjacent vertebrae (ball and socket type joint)
2. Tubercle of rib with the transverse process of the corresponding vertebra (plane type joint).