cervical vertebrae

Examples of cervical vertebrae in the following topics:

• Regional Vertebral Characteristics

  • The vertebrae of the spinal column are divided into several regions: cervical, thoracic, lumbar, sacral, and coccyx.
  • For example, the most superior cervical vertebrae is termed C1 and the most inferior C7, which is then followed by the T1 vertebrae of the thoracic region.
  • The cervical region of the spine is the most superior and contains seven small vertebrae.
  • The twelve thoracic vertebrae are located inferiorly to the cervical region.
  • They are larger than the cervical vertebrae and increase in size moving inferiorly to the lumbar region.

• Fractures of the Vertebral Column

  • They can affect the cervical vertebrae (a cervical fracture), the thoracic, or the lumbar regions.
  • A compression fracture is a collapse of vertebra.
  • It may be due to trauma or a weakening of the vertebra.
  • A cervical fracture is commonly called a broken neck .
  • There are seven cervical vertebrae (neck bones) in the human neck, and the fracture of any can be catastrophic.

• General Characteristics of the Spine

  • The spine is made of vertebrae that link together to protect the spinal cord.
  • There are 33 vertebrae in the human spine which are split into five regions which correspond to the curvature of the spine; the cervical, thoracic, lumbar, sacrum and coccyx.
  • The vertebrae of the sacrum and coccyx have fused whilst those of the cervical, thoracic and lumbar regions are separated by intervertebral discs.
  • For example, the most superior cervical vertebra is termed C1 and the most inferior C7, which is then followed by the T1 vertebrae of the thoracic region.
  • The cervical curve covers the region between vertebrae C1 and T2, it is the least marked of all the spinal curves.

• The Spine

  • The upper three regions comprise the remaining 24, and are grouped as cervical (seven vertebrae), thoracic (12 vertebrae) and lumbar (five vertebrae).
  • The spinous processes of the cervical and lumbar regions can be felt through the skin.
  • The cervical curve convexes forward and begins at the apex of the odontoid (tooth-like) process, and it ends at the middle of the second thoracic vertebra.
  • As the child grows, lifts the head, and begins to assume an upright position, the secondary curves (cervical and lumbar) develop.
  • The cervical curve forms when the infant is able to hold up its head (at three or four months) and to sit upright (at nine months).

• Parts of a Vertebra

  • A vertebra consists of two parts: an anterior segment, or the vertebral body; and a posterior part, or the vertebral (neural) arch.
  • When articulated together the vertebrae form a strong yet flexible structure which encloses the vertebral foramen, or opening, in which the spinal cord sits; whilst also providing a base for numerous muscle attachments and articulations with other bones.
  • The strength and flexibility of this structure is generated by the structure of the individual vertebrae.
  • Comprised of bone and cartilage the configuration of a vertebrae varies based on its location within the body, although there are common features associated with those of the upper region.
  • A typical vertebra of the upper region of the spine consists of two regions; the anterior vertebral body which is the point of articulation between the vertebrae and the posterior vertebral or neural arch which encloses the spinal cord.

• Cervical Plexus

  • The cervical plexus is the plexus of the ventral rami of the first four cervical spinal nerves.
  • The cervical plexus is a plexus of the ventral rami of the first four cervical spinal nerves which are located from the C1 to C4 cervical segment in the neck.
  • The cervical plexus has two types of branches: cutaneous and muscular.
  • Lesser occipital nerve - The lesser occipital nerve or small occipital nerve is a cutaneous spinal nerve arising between the second and third cervical vertebrae, along with the greater occipital nerve.
  • Transverse cervical nerve - The transverse cervical nerve (superficial cervical or cutaneous cervical) arises from the second and third cervical nerves, turns around the posterior border of the sternocleidomastoideus about its middle, and, passing obliquely forward beneath the external jugular vein to the anterior border of the muscle, it perforates the deep cervical fascia and divides beneath the platysma into ascending and descending branches, which are distributed to the antero-lateral parts of the neck.

• Trachea

  • It commences at the lower border of the larynx, level with the sixth cervical vertebra, and bifurcates into the primary bronchi at the vertebral level of thoracic vertebra T5, or up to two vertebrae lower or higher, depending on breathing.

• Overview of the Spinal Nerves

  • Thus the cervical nerves are numbered by the vertebra below, except C8, which exists below C7 and above T1.
  • The thoracic, lumbar, and sacral nerves are then numbered by the vertebra above.
  • In the case of a lumbarized S1 vertebra (i.e., L6) or a sacralized L5 vertebra, the nerves are typically still counted to L5 and the next nerve is S1.
  • The anterior distribution includes the cervical plexus (C1-C4) and brachial plexus (C5-T1).
  • A loop of nerves called ansa cervicalis is part of the cervical plexus.

• Overview of the Spinal Cord

  • The spinal cord has a varying width, ranging from 0.5 inch thick in the cervical and lumbar regions to 0.25 inch thick in the thoracic area.
  • The space between the dura mater and the surrounding bone of the vertebrae is called the epidural space.
  • The spinal cord is divided into cervical, thoracic, and lumbar regions.
  • The cervical region is divided into eight levels that are related to different motor and sensory functions in the neck and the arms.
  • The spinal nerve emerges from the spinal column through the opening (intervertebral foramen) between adjacent vertebrae.

• Branches of Spinal Nerves

  • Major plexuses include the cervical, brachial, lumbar, and sacral plexuses.
  • The meningeal branches (recurrent meningeal or sinuvertebral nerves): These branch from the spinal nerve and re-enter the intervertebral foramen to serve the ligaments, dura, blood vessels, intervertebral discs, facet joints, and periosteum of the vertebrae.