Intervertebral Disc: Classification and Embryology Flashcards
Based on histology, what is the classification of the intervertebral disc?
cartilaginous (amphiarthrosis) symphysis
Based on function, what is a possible classification for the intervertebral disc?
a synovial (diarthrosis) arthrodia
How do the parts of the intervertebral disc reflect the parts of a synovial (diarthrosis) joint?
- the annulus fibrosus is comparable to the fibrous capsule
- the nucleus pulposus is comparable to the synovial fluid
- the cartilage end plate is comparable to the articular cartilage
What is the earliest indicator of intervertebral disc pathology or degeneration?
changes in the histology of the cartilage end plate
What are the divisions of the embryonic somite?
- sclerotome
- myotome
- dermatome
What part of the somite will form the vertebral column?
sclerotome
What structure is formed following migration of sclerotomes to surround the notochord?
the perichordal blastema
What is formed following differential mitosis within the perichordal blastema?
- a loose cranial sclerotomite
- a dense caudal sclerotomite
What is formed within the perichordal blastema between the sclerotomites?
the intrasclerotomal fissure or fissure of von Ebner
What does the intrasclerotomal fissure become?
the perichordal disc
What will the dense sclerotomite become?
the upper part of the vertebral segment forming below
What will the loose sclerotomite become?
the lower part of the vertebral segment forming above
What structure forms following migration and subsequent mixing of the sclerotomites?
the vertebral blastema
What forms the upper part of the vertebral blastema?
the dense caudal sclerotomite of the perichordal blastema above
What forms the lower part of the vertebral blastema?
the loose cranial sclerotomite of the perichordal blastema below
