boulderleft.blogg.se - Anterior vertebral arch

The secondary centres on the tips of the transverse and spinous processes contribute to the length of these. Individual primary centres start to ossify at different ages, but in general terms, ossification starts in the latter half of the embryonic period and the centres begin to fuse around the time of birth.ĭuring puberty, five secondary ossification centres develop in each vertebra. Occasionally the two neural arch centres do not fuse in the midline, which is known as an unfused spinous process. The neurocentral joint is where these ossification centres meet in the posterior vertebral body. lumbar spine (5 vertebrae) are the biggest and strongest, with the least movementĮach vertebra forms in the embryo around the notochord from three primary ossification centres: an anterior midline centrum which forms most of the vertebral body and two bilateral posterolateral centres which form the two halves of the neural arch and the portion of the vertebral body posterior to the costal elements.

thoracic spine (12 vertebrae) contribute to the thoracic cage.

cervical spine (7 vertebrae) are the most mobile.

The vertebrae are grouped together based on similar osteology and regional relations which are dependant on function: Four small caudal rudimentary vertebrae fuse to form the coccyx. There are 24 vertebrae stacked on top of each other separated by intervertebral discs. In addition, there are five sacral vertebrae which are fused into a single bone, the sacrum.

In the cervical spine, from C3-C7, bilateral uncinate processes are found along the lateral aspect of the superior vertebral bodies.

In the axial plane, this lies between the pedicle and the lamina on each side.

in the lumbar spine, a span of bone exists between the superior and inferior articular processes bilaterally, which is known as the pars interarticularis.

a single spinous process project posteriorly from the laminae in the midline.

bilateral superior articular processes are lined with synovial cartilage and project posterosuperiorly from where the pedicles and laminae fuse, medial to the base of the transverse processes.

bilateral inferior articular processes are lined with synovial cartilage and project posteroinferiorly from where the pedicles and laminae fuse, medial to the base of the transverse processes.

bilateral transverse processes project posterolaterally from where the pedicles and laminae fuse.Seven processes arise from the neural arch, that provides articular support and attachments for ligaments and muscles: the laminae are bilateral, flattened plates that extend posteromedially from the posterior margin of the pedicles, to meet in the midline forming the posterior wall of the vertebral foramen.The superior and inferior margins of each pedicle are slightly curved and form the vertebral notches, which when an adjacent vertebra is joined, create the intervertebral (or neural) foramina which transmit the nerve roots and associated vessels They join with the lateral aspects of the laminae posteriorly. the pedicles which are short, thick bilateral processes that protrude posteriorly from the posterolateral corner of the vertebral body forming the lateral walls of the vertebral foramen.The neural arch is comprised of the bone posterior to the vertebral body which has several individual components that are fused to form a ring (the vertebral foramen) that encloses the spinal canal.

Each vertebra articulates with the vertebrae above and below it via an intervertebral disc. The size of the vertebral bodies increases down the spine as the size and weight of the body it has to support above it increase. The vertebral body is the large anterior cylindrical portion that is predominantly responsible for bearing the weight of the spine and body above it. These basic characteristics vary depending on the function of each individual vertebra. Vertebrae, apart from those that are atypical, have a similar basic structure which can be described as an anterior vertebral body and a posterior neural (or vertebral) arch.