Intervertebral Disc: Classification & Embryology Flashcards
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 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 crura 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
