Anatomy

Question 1

Atlas
Spinous proces?
Vertebral body?

Answer 1

Spinous process is absent
Spinous Process is absent
Transverse Process
Modified into wing or ala that projects laterally  Segmental contact point
Vertebral Body is absent
Dorsal Arch
Strong dorsal roof of vertebral canal  Segmental contact point

Question 2

Occiput- Atlas Motion Unit (Co-C1)

C0-C1 joint

View Page 14

Answer 2

Occiput- Atlas Motion Unit (C0-C1)
Atlantooccipital Joint
• Articulation between atlas and occiput
• Range of motion is lateral flexion and flexion-extension
• Condyles of occiput limit rotation
• Joint capsule is roomy for extensive movement

Dorsal Longitudinal Ligament
• Extends from dorsal arch of atlas to dorsal foramen magnum Ventral Longitudinal Ligament
• Extends from ventral arch to ventral margin of foramen magnum
• Fuses with joint capsule
• Modified dorsal longitudinal ligament Lateral Ligaments
• Two short bands from lateral atlas wing to jugular process of occiput

Question 3

Atlas -Axis motion Unit C1-C2

Answer 3

Atlantoaxial Joint
Atlas – Axis Motion Unit (C1-C2)
• Articulation between atlas and axis
• Saddle-shaped facets allow rotation
• Dens protrudes onto floor of vertebral canal
Joint Capsule
• Roomy and allows extensive movement
Modification of interspinous ligament
• extends from dorsal arch of atlas to spine of axis
Longitudinal ligament
• Short, strong ligament from dens to floor of vertebral canal in atlas Ligament oft the Dens
• Thin bundle extending from apex of dens to occiput through vertebral canal

Question 4

Typical Cervical Vertebrae
Which ones are they?
Tell me about their general description.

Answer 4

C3-C5
Spinous process
• Low ridge in typical cervical • Least prominent at C3
• Not palpable
Transverse Process
• Flat, wing-like angling caudally
• Palpated ventral to lamina-pedicle junction
Transverse foramen transmits the vertebral artery and nerve
Articular Processes
• Cranial Articular Processes: bear flat facets that extends off cranial lamina • Face medial, cranial and dorsal
• Caudal Articular Processes: extends off caudal lamina
• Face ventral, caudal, and lateral
• Facet joints: Approximately 45 degree angle

Vertebral Canal
Typical Cervical Vertebra: C3-C5
• Flattened dorso-ventrally
• Larger dimensions than in the thoracic region
Lamina-Pedicle junction
• Lamina forms broad shelf in cervical region
• Pedicle joins lamina medial to the lateral edge of lamina
• Curves inward between facets in the horse
Segmental Contact point for cervical adjusting
Vertebral Body
• Cranial body: surface for attachment of disc, convex in quadruped • Larger the animal the more accentuated the convexity
• Caudal body attachment of disc, concave
• Articulation of bodies resembles a ball and socket joint
• Bodies of cervical vertebra are longer than anywhere in column
• Ventral midline ridge

Question 5

Describe the Atypical Cervical Vertebrae

Answer 5

C6, C7
Transition segments more similar to thoracic vertebrae
-Vertebral body is shorter, ventral ridge is reduced
-transverse Process with 2 branches
-short, thickened lateral branch
-wide plate- like ventral branch (canine)

Seventh Cervical Canine:
-SP is prominant and angles cranially, body is shortened
-caudal articular processes are widley spaced and project well off lamina
-transverse process is rediced to one cranial process which is positioned more
cranially off vertebral body than in other cervical vertebrae
• Seventh cervical articulates with first ribs