Vertebral Column 3 Flashcards
how many articular facets are there per vertebra
4 –> 2 cranial and 2 caudal
what is the orientation of the articular facets
cranial facets lateral/ventral to caudal facets
what are the exceptions to the synovial joint features (3)
- atlanto-occipital joint where the atlas or C1 articulates with the occipital condyles of the skull rather than adjacent vertebra
- sacrum –> bones are fused into single bone unit –> articular facets and associated joints are absent
- caudal/coccygeal region –> vertebra have reverted to more basic form and have lost many of features associated with typical vertebra including articular facets
what are the features of synovial joints
synovial fluid is present between articular surfaces
produced by synovial membrane and contained within the joint capsule
stabilized by ligaments and movement across joints produced by action of muscle
what is the intervertebral disc made up of
- annulus fibrosus
- nucleus pulposus
what is the annulus fibrosus
series of concentric rings of fibrous tissue arranged in rigns (like onion)
fibres run between endplates of adjacent vert bodies –> holding them together + providing stability by restricting stretching of intervertebral disc space
what is the nucleus pulposus
notochord remnant –> involved with embryological development of vert column
jelly filled cushion embedded within annulus fibrosis and surrounded by it –> shock absorption and resists compression of disc space
where is the intervertebral disc space weakest
annulus thinnest dorsally
what structures shown
- annulus fibrosus
- nucleus pulposus
what are the intervertebral ligaments
- dorsal longitudinal ligament
- ventral longitudinal ligament
- interspinous ligaments
- interarcuate/yellow ligament
- supraspinous ligament
- nuchal ligament - dog
where does the dorsal longitudinal ligament run
along the dorsal aspect of the vertebral bodies –> ventral floor of the vertebral canal
along the entire length of the vertebral column from the level of C2
name the ligaments shown
- dorsal longitudinal ligament
- ventral longitudinal ligament
- invertebral disc
- interspinous ligaments
- interarcuate/yellow ligament
where does the ventral longitudinal ligament run
ventral aspect of the vertebral body and is present from the level of C2 to the sacrum
where does the supraspinous ligament run
along dorsal aspect of dorsal spinous processes and is present from level of T1 to CC3
in dog it continues in cranial driection to caudal aspect of axis or C2 as a cord of fibroelastic material called nuchal ligament
what is the function of the nuchal ligament
passive support for the large weight of head
how does the nuchlar ligament differ in horses
heavier head –> 2 parts
- funicular part = cord: fibro-elastic band of tissue (present in dog) is a continuation of supraspinous ligament runs all the way to nuchal crest of skull
- laminar part = fenestrated sheet: run from funicular part of nuchal ligament to dorsal spinous processes of cervical vertebrae
what is present near the nuchal ligament in horses
- fluid filled bursa –> atlantal bursa (located between nuchal ligament and atlas/C1
- supraspinous bursa –> dorsal to the dorsal spinous processes of the first few thoracic vertebrae
what are the ribs held in place by
costal ligaments