Axial Skeleton Flashcards
Canine / Feline vertebral formula
C7 T13 L7 S3 Cd ~20-23
Equine verterbral formula
C7 T18 L6 S5 Cd 15-21
Bovine vertebral forumla
C7 T13 L6 S5 Cd 18-20
Common feat of each vertebrae
vertebral foramina (vertebral arches and vertebral body)
vertebral notches
spinous processes
articular processes
C1
atlas
contain lateral vertebral foramina
articulates with occipital condyles
dorsal surface of ventral arch contains the fovea of the dens
the lateral formina allows for passage of the first cervical spinal nerves
C2
Axis elongated dorsal spinous process dens (odontoid process): a cranioventral peg-like eminence held down by a transverse ligament
C6
higher spinous process
EXPANDED TRANSVERSE PROCESS
C7
NO transverse foramina
Highest spinous process of cervical vertebra
Thoracic vertebra
have elongated spinous processes
cranial and caudal costal fovea for rib attachment
T11 is anticlinal vertebrae (transitional segment between thoracolumbar region)
Ribs
bony and cartilaginous component
1-9 true ribs (connect to sternum) (vertebrosternal)
10-12 articulate with cartilage of cranial ribs (vertebrocartilaginous)
13- floating rib (vertebral)
Rib articulation
Heads of ribs 1-10 articulate with cranial costal fovea of same vertebra and caudal costal fovea of the preceding vertebrae
Heads of ribs 11-13 will articulate with same vertebrae (cranial costal fovea)
TUBERCLE OF EACH RIB WILL ARTICULATE WITH THE TRANSVERSE FOVEA OF THE SAME VERTEBRAE
Lumbar
longer bodies than thoracic
spinous processes all point cranially toward T11
Sacrum
fused in dog
articulates with ilium
sacral promontory is dorsal boundary of the pelvic inlet
on dorsal and ventral aspect you have 2 foramina for sacral spinal nerves
Spondylosis Deformans
degeneration that is usually seen in older dogs that if severe can cause discomfort
Thoracic lumbar and lumbosacral regions
possible secondary changes to intervertebral disc disease
decreasing motion seen in weak joints
De
Discospondylitis
infection of the vertebrae and intervertebral disc thoracolumbar and lumbosacral areas hematogenous spread (goes through bloodstream either a fungus or bacteria) or a local infection (usually due to migrating foreign body)
Caudal vertebrae
anywhere from 6-23 (dog)
average is 20
hemal arches present to protect the medial caudal artery
Nuchal ligament
yellow elastic fibers
attach to caudal part of the spinous process of the axis
extends to the spinous process of T1
not present in Cat
in large animal goes to the NUCHAL CREST OF THE SKULL
in LA has two parts: funicular part (cord-like dorsally located) and laminar part (sheet-like, extends between the dorsal fuicular part and cervical vertebrae)
Synovial bursa are interposed between the funicular part of the nuchal ligament and certain body prominences in the large animal; infections and inflammations of these bursa result in “poll evil” and “fisulous whithers”
Ventral longitudinal ligament
located on the ventral surface of the vertebral bodies From sacrum (s1-s3) to axis (C2)
Dorsal Longitudinal ligament
located on the dorsal surface of vertebral bodies, ventral to the spinal cord
from caudal vertebra 1 (Cd 1 ) to axis (C2)
Supraspinous ligament
extends from the spinous processes of T1-Cd3
attaches to the apices of the spines
sternum
unpaired
8 bones
ventral boundary of thorax
joined by cartilage (intersternal cartilage)
manubrium : 1st sternebrae, longer than the rest
xyphoid process: last sternebrae, short and flat, cartilage projecting caudally : xyphoid cartilage
Alanto-occipital joint
between the atlas and occipital condyles
dorsal and ventral atlanto-occipital membranes: CSF removal
lateral ligament from the lateral dorsal arch to the paracondylar process of the occipital bone
commonly known as the yes joint
Atlanto-axial joint
commonly konwn as the no joint
apical ligament of the dens: dens to the basi-occipital bone (near forament magnum)
Alar ligaments: attach dens on either side of apical ligament to the occipital bone
Transverse atlantal ligament: connects one side of the ventral arch to the other. hold dens against ventral arch
Atlanto-axial instability
uncommon
abnormal movement in the neck
compression of the spinal cord
2 causes: birth defect or trauma
intervertebral discs
in each intervertebral space (except c1-c2)
composed of annulus fibrosus (outer laminated fibrous ring(
nucleus pulposus (central gelatinous center)
Stress absorber
the degeneration of the annulus fibrosus can lead to IVDD
Intervertebral Disc Disease
Herniated disc
2 types
compressive and concussive
chondrydystrophic (3-6 years of age, dachshunds)
non chonrodystrophic (5-12 years) labs german shepherds
Calcification of the disc
Interspinous ligament
connects adjacent vertebral spines
yellow ligaments
between the arches of the adjacent vertebrae
epidural spaces lies ventral to these ligaments
intercapital ligaments
from the head of the rib over the intervertebral disc to the head of the opposite rib
the extra support over the disc helps decrease the occurence of disc disease in the thoracic vertebrae
costotransverse ligament
largest ligament attaching the rib to the vertebrae
muscles of the axial skeleton
epaxial
extensors of the vertebral column found dorsal to the transverse process iliocostalis longissimus transversospinalis
the caudal portions can be indistinguishable
Iliocostalis lumborum
Ilium to last four or five ribs
iliocostalic thoracis
12th rib to the 7th cervical vertebrae
• Longissimus thoracis et lumborum
Ilium to the thoracic vertebrae
• Just medial to the iliocostalis
system
• Longissimus cervicis
• Cranial continuation into the
neck
• Longissimus capitis
• Medial to longissimus cervicis and splenius • First 3 thoracic vertebrae to the mastoid part of the temporal bone • United with the splenius
• Transversospinalis
Most medial system • Sacrum to the head • Splenius • Deep to rhomboideus capitis and serratus dorsalis cranialis
• Semispinalis capitis
• Biventer cervicis
dorsally
• Complexus
ventrally
Hypaxial muscles
• Ventral to the transverse processes • Flexors of the vertebral column • Longus capitis m. • Lies on the lateral surface of the cervical vertebrae • Longus colli m. • Covers the ventral surfaces of the vertebral bodies form the 6th thoracic vertebrae to the atlas
• The longus capitis and the
longus colli
are considered the
dorsal border of the cervical
visceral space
Contains • Trachea • Esophagus • Carotid sheath • Thyroid and parathyroid glands