The Development of the Vertebral Column: Origin from Somites
- Mesenchymal cells from sclerotome of somites form condensations around the neural tube and notochord.
- Condensation and proliferation of caudal half of one sclerotome join cranial half of next sclerotome to form a vertebral body
Vertebral bodies develop from the caudal half of one sclerotome and the cranial half of the succeeding sclerotome.
- Anulus fibrosus of intervertebral disc is formed from mesenchymal cells of sclerotome that fill space between adjacent vertebral bodies as they form
Figure Development of vertebral column. A, Caudal and cranial halves of adjacent sclerotomes fuse to form vertebral bodies . B, Note position of segmental neurovascular structures and myotomes relative to developing vertebral bodies. Intervertebral discs develop in middle of original sclerotomes. C, Muscles that develop from myotomes bridge intervertebral discs and move adjacent vertebrae.