S3 Arthrology of the Vertebral Column Flashcards
What is the reason that 9 common ligaments are identified but only 8 will be attached at any specific vertebral couple?
the ligamentum nuchae and supraspinous ligaments attach to the spinous tubercles, but only 1 of these will be identified at a single vertebral couple
What is the number of true intervertebral discs identified in the adult?
23
In the adult, which vertebral levels will demonstrate a true intervertebral disc?
those between C2 and S1 inclusive
What is the percent of intervertebral disc height contribution to the length of each region of the vertebral column?
cervical…22-25%; thoracic….20%; lumbar….33%
What are the names of the central, peripheral, and horizontal zones of the intervertebral disc?
nucleus pulposus… central zone; annulus fibrosus…peripheral zone; cartilaginous end plate….horizontal zone
What is the water concentration in the lumbar nucleus pulposus at birth and after 30?
birth…..88%; thirty…..70%
What is the consequence of non-aggregated glycosaminoglycans in the lumbar nucleus pulposus?
the nucleus pulposus will loose water under deformation conditions
What cell is associated with the nucleus pulposus until about age 11?
notochord cells
Which type of collagen is dominant in the nucleus pulposus?
collagen type II
What is the organizational pattern for collagen fibers in the nucleus pulposus?
they are irregularly oriented and randomly scattered
What is the appearance of the cervical annulus fibrosus?
a horse-shoe with the anterior margin thick and the lateral margins tapering to the uncinate processes; the posterior margin is thin
What compensates for the thinness of the posterior part of the cervical annulus fibrosus?
posterior longitudinal ligament
What is the organization of the lumbar annulus fibrosus?
it has 12-14 concentric cylindrical lamellae
What is the water concentration in the lumbar annulus fibrosus at birth and after thirty?
birth…..78%; thirty…..70%
What is the organizational pattern for glycosaminoglycans in the lumbar annulus fibrosus?
they typically have a binding site for hyaluronic acid and are thus aggregated
Which type of collagen is dominant in the annulus fibrosus?
collagen type I
What is the organizational pattern for collagen fibers in the annulus fibrosus?
they are parallel with 1 another in a single lamellus and angled
What is the organization of collagen fibers between lamellae?
collagen fibers will be angled in the opposite direction such that a spiral - counterspiral organization is observed
What is the attachment site for collagen fibers within the annulus fibrosus?
collagen fibers of the outer lamellae will become Sharpey’s fibers and penetrate the epiphyseal rims; collage fibers of the inner lamellae will attach to the cartilaginous end plate
What is the origin for the cells of the annulus fibrosus?
sclerotomites
What is the principal type of collagen fiber within the cartilage end plate?
the type II collagen fiber
What is the direction of collagen fibers within the cartilage end plates?
anterior to posterior
What is the attachment site for collagen fibers of the inner lamellae of the annulus fibrosus?
cartilaginous end plate
What are the types of receptor endings in the intervertebral disc?
nociceptors and proprioceptors
What is the relationship between size of the intervertebral disc and receptor endings?
the larger the disc, the greater the variety of receptor endings
What part of the intervertebral disc is innervated by the recurrent meningeal/sinu-vertebral/sinus vertebral nerve?
the outer lamellae of the annulus fibrosus at the posterior part of the intervertebral disc
What forms the anterior neural plexus of the vertebral column?
fibers from the ventral primary ramus
What forms the lateral neural plexus of the vertebral column?
ventral primary ramus
white ramus communicans
paradiscal ramus communicans
gray ramus communicans
What is the name given to the white ramus communicans which becomes embedded within the annulus fibrosus of the intervertebral disc?
paradiscal ramus communicans
What part of the intervertebral disc is innervated by fibers from the paradiscal ramus communicans?
outer lamellae of the annulus fibrosus at the lateral part of the intervertebral disc
What is the maximum number of common ligaments identified with a vertebral couple?
eight
How does the intervertebral disc attach to the vertebral body?
Sharpey’s fibers from the outer lamellae of the annulus fibrosus are firmly embedded into the epiphyseal rims of the adjacent vertebral bodies
Based on histology, what is the classification of the intervertebral disc?
a cartilaginous (amphiarthrosis) symphysis
What are the divisions of the embryonic somite?
the sclerotome, myotome, and dermatome
What structure is formed following migration of sclerotomes to surround the notochord?
the perichordal blastema
What is formed within the perichordal blastema between the sclerotomites?
the intrasclerotomal fissure or fissure of von Ebner
What does the intrasclerotomal fissure or fissure of von Ebner become?
the perichordal disc
What will the dense sclerotomite become?
the upper part of the vertebral segment forming below
What structure forms following migration and subsequent mixing of the sclerotomites?
the vertebral blastema
What structure forms following migration and subsequent mixing of sclerotomites?
the vertebral blastema
What part of the intervertebral disc will the notochord form?
the nucleus pulposus
What part of the intervertebral disc will the perichordal disc form?
the annulus fibrosus
What is the earliest indicator of the position of the adult intervertebral disc?
the intrasclerotomal fissure or fissure of von Ebner
What vertebral levels will the anterior longitudinal ligament attach to?
those between occiput and S3 inclusive are traditionally indicated
What is the lowest extent of the anterior longitudinal ligament based on recent studies?
L3
What is believed to form the anterior longitudinal ligament in the lumbar spine?
the tendon of the cura of the diaphragm
What innervates the anterior longitudinal ligament?
the anterior neural plexus formed by fibers from the ventral primary ramus and sympathetic postganglionic fibers from the paravertebral ganglia
What is the function of the anterior longitudinal ligament?
it brakes or limits dorsi-flexion or hyperextension of the vertebral column
What is ossification of the anterior longitudinal ligament in the lumbar region now identified as?
Diffuse Idiopathic Skeletal Hyperostosis or DISH
Newer research suggests what regional variation in the posterior longitudinal ligament?
prominent in the cervicals, occasional in the thoracics, rare in lumbars
What is the relationship of the posterior longitudinal ligament to the vertebral foramen?
it forms the anterior boundary of the spinal canal?
What is the appearance of the posterior longitudinal ligament in the lumbar spine?
it is hourglass shaped along its lateral margins
What is the innermost layer of the posterior longitudinal ligament called?
the perivertebral ligament
What is the function of the posterior longitudinal ligament?
it brakes or limits flexion of the vertebral column
Where is ossification of the posterior longitudinal ligament most commonly identified?
the cervical spine with an 80% incidence
What is the clinical sign of posterior longitudinal ligament ossification of the cervical spine?
a loss of hand and finger dexterity
What is the clinical sign of posterior longitudinal ligament ossification in the lumbar spine?
faltering gait
What is the gender, age, and ethnic bias associated with ossification of the posterior longitudinal ligament?
it is greater in males over 50 and has a higher incidence in the Japanese
What is the name given to the ligamentum flavum based on appearance and histology?
it is a yellow elastic ligament
What fibers are most ligaments made up of?
collagen type I fibers which are whitish in appearance
Where is ossification of the ligamentum flavum most commonly identified?
the thoracic spine or thoracolumbar transition zone
What is the relationship between the capsular ligament and mobility?
the more lax/loose the capsular ligament is, the greater the motion of the joint
What regions of the vertebral column demonstrate the greatest laxity of capsular ligaments?
the cervical and lumbar regions
What layers are present in the capsular ligament?
a superficial layer of collagen fibers and a deep layer of elastic fibers
If the zygapophyseal capsular ligament is not significantly involved in restricting motion what is its’ function?
it is probably involved in proprioceptive feedback to the muscles stabilizing the vertebral couple during movement
What is now thought to be a major function of the interspinous ligament?
it is more likely a proprioceptive transducer for the spinal reflex
What is the name given to the superficial layer of the ligamentum nuchae?
the funicular layer or part
What is the name given to the deep layer of the ligamentum nuchae?
the lamellar layer or part
What are the attachment sites for the superficial layer of the ligamentum nuchae?
the external occipital protuberance, external occipital crest, and spinous tubercle of C7?
What is the histological make-up of the human ligamentum nuchae?
it is a yellow elastic ligament, but has more collagen fibers than in quadrupeds
What is the classic function of the human ligamentum nuchae?
it brakes or limits flexion of the cervical spine
What is the termination level inferiorly for the supraspinous ligament according to current literature?
primarily at L4 (73%); between L4 and L5 (5%)
What is now thought to be a major function of the supraspinous ligament?
it is a proprioceptive transducer for the spinal reflex
