Both the vertebral body and the discs increase in size from the head to the sacrum. Each vertebra has two cylinder-shaped projections pedicles of hard bone that stick out from the back part of the vertebral body, providing side protection for the spinal cord and nerves. The pedicles also serve as a bridge, joining the front and back parts of the vertebra. The lamina is is the roof of the spinal canal that provides support and protection for the backside of the spinal cord.
The bumps that can be felt down the back are the spinous processes. They are bony projections that arise at right angles perpendicular to the midline of the lamina.
Each spinous process is attached to the spinous process above and below it by ligaments. Sometimes these processes are absent or bifid in the cervical spine. The transverse processes are located at right angles to the junction of pedicles and the lamina. They provide a place for the back muscles to attach to the spine. For the most part, these are absent in the vertebra of the neck the cervical spine. If present in the cervical spine they occur at the lowest level C7 and are called a cervical rib.
They may impair exiting nerve roots and cause pain. The spinal canal is a bony tunnel surrounding the spinal cord. It is made up of the front anterior of the vertebral body, the pedicles on the sides of the vertebral body and the lamina in the back.
In the lower back it not only contains the spinal cord, it also contains the nerve roots of the lower spine. Each vertebra has a paired joint on its right side and a second paired joint on its left side, allowing a connection with the vertebrae above and below it. The pair that faces upward is the superior articular facet. The pair that faces downward is the inferior articular facet.
The facet complex is surrounded by a watertight synovial capsule, much like the small joints in the fingers that allow for smooth movement. Skip to content. Vertebrae of the Spine Not what you're looking for? Start New Search. About the vertebrae of the spine The adult spine is made up of approximately 24 bones vertebrae stacked on top of each other from the bottom of the skull to the pelvis.
Vertebral Body The vertebral body is the main portion of the vertebra. Pedicles Each vertebra has two cylinder-shaped projections pedicles of hard bone that stick out from the back part of the vertebral body, providing side protection for the spinal cord and nerves.
Cervical vertebrae usually have a bifid Y-shaped spinous process. The spinous processes of the C3—C6 vertebrae are short, but the spine of C7 is much longer. You can find these vertebrae by running your finger down the midline of the posterior neck until you encounter the prominent C7 spine located at the base of the neck.
The transverse processes of the cervical vertebrae are sharply curved U-shaped to allow for passage of the cervical spinal nerves. Each transverse process also has an opening called the transverse foramen. An important artery that supplies the brain ascends up the neck by passing through these openings. The superior and inferior articular processes of the cervical vertebrae are flattened and largely face upward or downward, respectively.
The first and second cervical vertebrae are further modified, giving each a distinctive appearance. The first cervical C1 vertebra is also called the atlas , because this is the vertebra that supports the skull on top of the vertebral column in Greek mythology, Atlas was the god who supported the heavens on his shoulders. The C1 vertebra does not have a body or spinous process. Instead, it is ring-shaped, consisting of an anterior arch and a posterior arch.
The transverse processes of the atlas are longer and extend more laterally than do the transverse processes of any other cervical vertebrae.
The superior articular processes face upward and are deeply curved for articulation with the occipital condyles on the base of the skull. The inferior articular processes are flat and face downward to join with the superior articular processes of the C2 vertebra.
The second cervical C2 vertebra is called the axis , because it serves as the axis for rotation when turning the head toward the right or left. The axis resembles typical cervical vertebrae in most respects, but is easily distinguished by the dens odontoid process , a bony projection that extends upward from the vertebral body.
The dens joins with the inner aspect of the anterior arch of the atlas, where it is held in place by transverse ligament. The bodies of the thoracic vertebrae are larger than those of cervical vertebrae Figure 6. The characteristic feature for a typical midthoracic vertebra is the spinous process, which is long and has a pronounced downward angle that causes it to overlap the next inferior vertebra. The superior articular processes of thoracic vertebrae face anteriorly and the inferior processes face posteriorly.
These orientations are important determinants for the type and range of movements available to the thoracic region of the vertebral column. Thoracic vertebrae have several additional articulation sites, each of which is called a facet , where a rib is attached.
These are for articulation with the head end of a rib. An additional facet is located on the transverse process for articulation with the tubercle of a rib. Lumbar vertebrae carry the greatest amount of body weight and are thus characterized by the large size and thickness of the vertebral body Figure 6. They have short transverse processes and a short, blunt spinous process that projects posteriorly.
The articular processes are large, with the superior process facing backward and the inferior facing forward. The sacrum is a triangular-shaped bone that is thick and wide across its superior base where it is weight bearing and then tapers down to an inferior, non-weight bearing apex Figure 6.
It is formed by the fusion of five sacral vertebrae, a process that does not begin until after the age of The coccyx, or tailbone, is derived from the fusion of four very small coccygeal vertebrae see Figure 6. It articulates with the inferior tip of the sacrum. It is not weight bearing in the standing position, but may receive some body weight when sitting. Watch this second animation to see one possible treatment for a herniated disc, removing and replacing the damaged disc with an artificial one that allows for movement between the adjacent certebrae.
How could lifting a heavy object produce pain in a lower limb? Use this tool to identify the bones, intervertebral discs, and ligaments of the vertebral column.
The thickest portions of the anterior longitudinal ligament and the supraspinous ligament are found in which regions of the vertebral column? Chiropractors are health professionals who use nonsurgical techniques to help patients with musculoskeletal system problems that involve the bones, muscles, ligaments, tendons, or nervous system. They treat problems such as neck pain, back pain, joint pain, or headaches. If needed, they will refer the patient to other medical specialists.
Chiropractors use a drug-free, hands-on approach for patient diagnosis and treatment. They can recommend therapeutic or rehabilitative exercises, and some also include acupuncture, massage therapy, or ultrasound as part of the treatment program. In addition to those in general practice, some chiropractors specialize in sport injuries, neurology, orthopaedics, pediatrics, nutrition, internal disorders, or diagnostic imaging. To become a chiropractor, students must have 3—4 years of undergraduate education, attend an accredited, four-year Doctor of Chiropractic D.
With the aging of the baby-boom generation, employment for chiropractors is expected to increase. Skip to main content. Chapter 6: The Skeletal System.
Search for:. The Vertebral Column Learning Objectives Describe each region of the vertebral column and the number of bones in each region Discuss the curves of the vertebral column and how these change after birth Describe a typical vertebra and determine the distinguishing characteristics for vertebrae in each vertebral region and features of the sacrum and the coccyx.
Regions of the Vertebral Column. Curvatures of the Vertebral Column. Interactive Link Osteoporosis is a common age-related bone disease in which bone density and strength is decreased. General Structure of a Vertebra. Regional Modifications of Vertebrae.
Interactive Link Use this tool to identify the bones, intervertebral discs, and ligaments of the vertebral column.
Career Connections: Chiropractor Chiropractors are health professionals who use nonsurgical techniques to help patients with musculoskeletal system problems that involve the bones, muscles, ligaments, tendons, or nervous system.
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