Which ribs have demifacets

In addition to being connected to adjacent vertebrae, the thoracic vertebrae are also connected to ribs. The cervicothoracic junction is where the neck cervical spine connects with the upper back thoracic spine.

Conversely, the cervical spine above and lumbar spine below both have lordotic curves that go inward, toward the front of the body. Thoracic vertebrae T2 to T8 are all similar, although they do gradually get bigger while going down the spine.

A typical thoracic vertebra consists of the following:. See Facet Joint Anatomy Animation. While T2 through T8 are commonly considered typical thoracic vertebrae, there can be variations from person to person regarding which vertebrae are typical and which are unique. The following thoracic vertebrae have unique characteristics that distinguish them from the rest of the thoracic spine:.

A severe thoracic scoliosis curve may cause back muscles to become more prone to painful spasms. Read Scoliosis Symptoms. See Clinical Symptoms of Bone Spurs. The spine has several major roles in the body that include: protection of the spinal cord and branching spinal nerves, support for thorax and abdomen, and enables flexibility and mobility of the body.

The intervertebral discs are responsible for this mobility without sacrificing the supportive strength of the vertebral column. The thoracic region contains 12 vertebrae, denoted T1-T The intervertebral discs, along with the laminae, pedicles, and articular processes of adjacent vertebrae, create a space through which spinal nerves exit.

The thoracic vertebrae, as a group, produce a kyphotic curve. Thoracic vertebrae are unique in that they have the additional role of providing attachments for the ribs. Typical vertebrae consist of a vertebral body, a vertebral arch, as well as seven processes.

The body bears the majority of the force placed on the vertebrae. Vertebral bodies increase in size from superior to inferior. The vertebral body consists of a trabecular bone, which contains the red marrow, surrounded by a thin external layer of compact bone. The arch, along with the posterior aspect of the body, forms the vertebral spinal canal, which contains the spinal cord. The arch consists of bilateral pedicles, cylindrical segments of bone that connect the arch to the body, and bilateral lamina, bone segments form most of the arch, connecting the transverse and spinous processes.

A typical vertebra also contains four articular processes, two superior and two inferior, which contact the inferior and superior articular processes of adjacent vertebrae, respectively.

The point at which superior and articular facets meet is known as a facet, or zygapophyseal, joint. These maintain vertebral alignment, control the range of motion, and are weight-bearing in certain positions. The spinous process projects posteriorly and inferiorly from the vertebral arch and overlaps the inferior vertebrae to various degrees, depending on the region of the spine. Lastly, two transverse processes project laterally from the vertebral arch in a symmetric fashion. Typical thoracic vertebrae have several features distinct from those typical of cervical or lumbar vertebrae.

The primary characteristic of the thoracic vertebrae is the presence of costal facets. There are six facets per thoracic vertebrae: two on the transverse processes and four demifacets—the facets of the transverse processes articulate with the tubercle of the associated rib.

The demifacets are bilaterally paired and located on the superior and inferior posterolateral aspects of the vertebrae. They are positioned so that the superior demifacet of the inferior vertebrae articulates with the head of the same rib that articulates with the inferior demifacet of the superior rib.