Axial Skeleton and Muscles

Question 1

Vertebral Formulas

Cat/Dog, Horse, Ox

Answer 1

C/D: C7 - T13 - L7 - S3 - Cd - 20
H: C7 - T18 - L6 - S5 - Cd - 20
O: C7 - T13 - L6 - S5 - Cd - 20

Question 2

Cervical Vertebrae

Unique features

Answer 2

presence of a transverse foramen located in transverse processes (all but C7)
- vertebral artery, vein, and nerve run through

Question 3

Thoracic Vertebrae

Unique features

Answer 3

• elongated spinous processes (T1-T9)
• cranial and caudal costal foveae for rib attachment (only cranial on last 3 or 4)
• transverse costal foveae (tubercle of ribs attaches)
• mamillary and accessory processes

Question 4

Lumbar Vertebrae

Unique features

Answer 4

• large, ovoid shaped bodies
• spinous and transverse processes point cranially
• mamillary and accessory processes

Question 5

Sacral Vertebrae

Unique features

Answer 5

• fused in dog and cat
• articular surface of wing articulates with ilium
• sacral promontory is dorsal boundary of pelvic inlet
• fused spinous processes = median crest
• pelvic and dorsal foramina for sacral spinal nerves

Question 6

Caudal Vertebrae

Unique features

Answer 6

• hemal arches to protect the medial caudal artery

Question 7

Atlas

Answer 7

C1

• reduced, flattened body
• fovea dentis on floor of body
• lateral vertebral foramina for passage of cervical spinal nerves
• cranial and caudal articular foveae (articulate with occipital condyles and axis)

Question 8

Axis

Answer 8

C2

• elongated spinous process
• dens = extension of cranial vertebral body
• cranial articular surface (articulates with caudal articular fovea of atlas)

Question 9

C6

Answer 9

• ventral expansion of transverse processes

Question 10

C7

Answer 10

• no transverse foramina
• highest spinous process of cervical
• caudal costal foveae (articulates with first pair of ribs)

Question 11

T11

Answer 11

• anticlinal vertebra, spine is vertical

Question 12

Rib Articulation

Answer 12

• heads of ribs 1-10 articulate with the cranial costal fovea of the same numbered vertebra, and the caudal costal fovea of the preceding vertebra
• heads of ribs 11-13 articulate with cranial costal fovea of T11-T13
• tubercle of each rib articulates with the transverse fovea of same numbered vertebra

Question 13

Rib Structure

Answer 13

• ribs 1-9 (true ribs) connect to sternum
• ribs 10-12 articulate with cartilage of cranial rib
• rib 13 is floating

Question 14

Sternum Structure

Answer 14

• 8 sternabrae joined by intersternebral cartilages
• ventral boundary of thorax
• manubrium = first sternebra, longer
• xyphoid = last sternebra, short and flat, cartilage projects caudally

Question 15

Epaxial Muscles

Answer 15

• extensors of vertebral column
• lie dorsal to transverse processes
• iliocostalis, longissimus, transversospinalis

Question 16

Hypaxial Muscles

Answer 16

• flexors of vertebral column

- lie ventral to transverse processes

Question 17

Iliocostalis System

Answer 17

• most laterally located

- has lumbar and thoracic parts

Question 18

Longissimus System

Answer 18

• intermediately located

- parts: lumborum, thoracis, cervicis, and capitis

Question 19

Transversospinalis System

Answer 19

• most medially located
• from sacrum to head
• splenus
• semispinalis capitis (biventer cervicis and complexus)

Question 20

Cervical Visceral Space

Answer 20

Dorsal: longus colli and longus capitis
Ventral: sternocephalicus, sternothyroideus, and sternohyoideus
Contains: trachea, esophagus, carotid sheath, thyroid and parathyroid glands

Question 21

Supraspinous Ligament

Answer 21

connects apices of spinous processes from caudal vertebra to T1

Question 22

Nuchal Ligament

Answer 22

• continuation of supraspinous ligament
• from T1 to spine of axis (in dog)
• not present in cats
• goes to nuchal crest in large animals

Question 23

Ventral Longitudinal Ligament

Answer 23

• on ventral surface of vertebral bodies

- axis to sacrum

Question 24

Dorsal Longitudinal Ligament

Answer 24

• on dorsal surface of vertebral bodies, ventral to spinal cord
• axis to caudal vertebrae

Question 25

Intervertebral Discs

Answer 25

• in each intervertebral space (except C1-C2)
• anulus fibrosis = outer laminated fibrous ring
• nucleus pulposus = central, gelatinous center

Question 26

Interspinous Ligament

Answer 26

connects adjacent vertebral spines

Question 27

Yellow Ligaments

Answer 27

• between arches of adjacent vertebrae

- epidural space lies ventral to these ligaments

Question 28

Intercapital Ligament

Answer 28

• from head of rib, over the intervertebral disc, to the head of the opposite rib

Question 29

Costotransverse Ligament

Answer 29

attaches ribs to vertebrae

Question 30

Dorsal Atlantoaxial ligament

Answer 30

attaches to the cranial part of the spine of the axis and the dorsal arch of the atlas

Question 31

Transverse Ligament of the Atlas

Answer 31

• connects one side of ventral arch to the other

- holds dens against ventral arch

Question 32

Apical Ligament

Answer 32

dens to the basioccipital bone

Question 33

Alar Ligament

Answer 33

attach dens on either side of apical ligament to the occipital bone

Question 34

Spondylosis Deformans

Answer 34

• degeneration seen in older dogs
• thoracic, lumbar, and lumbosacral regions
• intervertebral disc weakens

Question 35

Discopondylitis

Answer 35

• infection of vertebrae and intervertebra disc
• thoracolumnar and lumbsacral regions
• hematogenous spread or local infection