Download Vertebral Ossification Centers:

Vertebral Ossification Centers:
Each typical vertebra has 3 primary ossification centers
Centrum – accounts for most of the body
each half of the neural arch
Neurocentral joints (see page 448)
primary cartilaginous joints
articulation between the halves of the neural arch and the centrum
Vertebral arch
cervical - fusion begins during first year
lumbar - complete by 6 years
the arch fuses to centrum 5-8 years of age
5 Secondary Ossification centers develop during puberty in each typical vertebra
tip of spinous process
tip of each transverse process
2 annular epiphyses (ring epiphyses) - one on superior and one on inferior edge of the centrum
unite with vertebral body in early adulthood
Secondary ossification centers become fused by age 25
Lumbar vertebra have secondary ossification centers for mammillary processes as well
The atlas
Primary center for each lateral mass and adjacent half of the posterior arch
Primary center for the anterior arch
Fusion occurs by age 8
The Axis
5 Primary centers
One for most of the body
One for each lateral mass
One for each half of the dens and adjacent part of the body
They fuse by three years of age
2 Secondary centers
The tip of the dens – appears at 2 years of age – fuses by age 12
Lower surface of the body – appears at puberty and fuses by age 25
The Sacrum
Represents 5 fused vertebra
Many ossification centers – centrum, neural arches, etc.
Fused by age 20
Costal Elements of Vertebra
Parts of cervical, lumbar and sacral vertebra represent the ribs that articulate with the thoracic vertebra
Cervical – anterior and posterior tubercle and costotransverse bar
Thoracic – true ribs
Lumbar – anterior portion of the transverse process
Sacral lateral portion to include the auricular surface