Axial Skeleton and Muscles Flashcards
Vertebral Formulas
Cat/Dog, Horse, Ox
C/D: C7 - T13 - L7 - S3 - Cd - 20
H: C7 - T18 - L6 - S5 - Cd - 20
O: C7 - T13 - L6 - S5 - Cd - 20
Cervical Vertebrae
Unique features
presence of a transverse foramen located in transverse processes (all but C7)
- vertebral artery, vein, and nerve run through
Thoracic Vertebrae
Unique features
- 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
Lumbar Vertebrae
Unique features
- large, ovoid shaped bodies
- spinous and transverse processes point cranially
- mamillary and accessory processes
Sacral Vertebrae
Unique features
- 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
Caudal Vertebrae
Unique features
- hemal arches to protect the medial caudal artery
Atlas
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)
Axis
C2
- elongated spinous process
- dens = extension of cranial vertebral body
- cranial articular surface (articulates with caudal articular fovea of atlas)
C6
- ventral expansion of transverse processes
C7
- no transverse foramina
- highest spinous process of cervical
- caudal costal foveae (articulates with first pair of ribs)
T11
- anticlinal vertebra, spine is vertical
Rib Articulation
- 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
Rib Structure
- ribs 1-9 (true ribs) connect to sternum
- ribs 10-12 articulate with cartilage of cranial rib
- rib 13 is floating
Sternum Structure
- 8 sternabrae joined by intersternebral cartilages
- ventral boundary of thorax
- manubrium = first sternebra, longer
- xyphoid = last sternebra, short and flat, cartilage projects caudally
Epaxial Muscles
- extensors of vertebral column
- lie dorsal to transverse processes
- iliocostalis, longissimus, transversospinalis
Hypaxial Muscles
- flexors of vertebral column
- lie ventral to transverse processes
Iliocostalis System
- most laterally located
- has lumbar and thoracic parts
Longissimus System
- intermediately located
- parts: lumborum, thoracis, cervicis, and capitis
Transversospinalis System
- most medially located
- from sacrum to head
- splenus
- semispinalis capitis (biventer cervicis and complexus)
Cervical Visceral Space
Dorsal: longus colli and longus capitis
Ventral: sternocephalicus, sternothyroideus, and sternohyoideus
Contains: trachea, esophagus, carotid sheath, thyroid and parathyroid glands
Supraspinous Ligament
connects apices of spinous processes from caudal vertebra to T1
Nuchal Ligament
- continuation of supraspinous ligament
- from T1 to spine of axis (in dog)
- not present in cats
- goes to nuchal crest in large animals
Ventral Longitudinal Ligament
- on ventral surface of vertebral bodies
- axis to sacrum
Dorsal Longitudinal Ligament
- on dorsal surface of vertebral bodies, ventral to spinal cord
- axis to caudal vertebrae
Intervertebral Discs
- in each intervertebral space (except C1-C2)
- anulus fibrosis = outer laminated fibrous ring
- nucleus pulposus = central, gelatinous center
Interspinous Ligament
connects adjacent vertebral spines
Yellow Ligaments
- between arches of adjacent vertebrae
- epidural space lies ventral to these ligaments
Intercapital Ligament
- from head of rib, over the intervertebral disc, to the head of the opposite rib
Costotransverse Ligament
attaches ribs to vertebrae
Dorsal Atlantoaxial ligament
attaches to the cranial part of the spine of the axis and the dorsal arch of the atlas
Transverse Ligament of the Atlas
- connects one side of ventral arch to the other
- holds dens against ventral arch
Apical Ligament
dens to the basioccipital bone
Alar Ligament
attach dens on either side of apical ligament to the occipital bone
Spondylosis Deformans
- degeneration seen in older dogs
- thoracic, lumbar, and lumbosacral regions
- intervertebral disc weakens
Discopondylitis
- infection of vertebrae and intervertebra disc
- thoracolumnar and lumbsacral regions
- hematogenous spread or local infection
