Cervical Vertebrae (Cervical Spine)

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Published on May 24th 2022 by

What is Cervical Vertebrae

Cervical vertebrae are the first seven ring-like bony structures of the vertebral column found in the neck region. These 7 bones are labeled C1 – C7, starting from top to bottom.

Where is the Cervical Vertebrae Located

As stated, cervical vertebrae are found in the neck region, starting from the base of the skull and extending to the thoracic cage of the trunk.

Quick Facts

Type         Irregular bones
Length and Widthi. In males: Approximately 71 cm
ii. In females: Approximately 61 cm
How many are there in the human body7
Articulates with Occipital bone (C1) and 1st thoracic vertebrae (C7)

Functions

  • Support the head’s weight and allow a wide range of head movements, like nodding and rotation.
  • Provide mobility to the neck.
  • Protect a part of the spinal cord.

Anatomy: Parts and Structure of Cervical Vertebrae

It is made up of 7 vertebrae. The first 2, C1 and C2, are highly specialized and given unique names: atlas and axis.

Cervical Vertebrae

1. Atlas (C1)

The Atlas, C1, is the topmost vertebra. It forms the joint with occipital bone, connecting the skull and spine. C1 has no individual body; its body remains fused with C2, the axis.

2. Axis (C2)

The Axis, C2, forms the pivot upon which the Atlas rotates. The most distinctive characteristic of this bone is the strong odontoid process (dens) that rises perpendicularly from the upper surface of the body. The body is deeper in front than behind, and prolonged downward anteriorly so as to overlap the upper and front part of the third vertebra.

Typical Cervical Vertebra (C3-C7)

1. Vertebral Body

The bodies of these four vertebrae are small, and transverse diameter is greater than anterio-posterior and height dimensions.

The anterior and posterior surfaces are flattened and of equal depth; the former is placed on a lower level than the latter, and its inferior border is prolonged downward, so as to overlap the upper and forepart of the vertebra below.

The upper surface is concave transversely, and presents a projecting lip posterolaterally on either side (Uncinate Process).

The lower surface is concave from front to back, convex from side to side, and presents laterally shallow concavities which receive the corresponding projecting lips of the underlying vertebra.

2. Vertebral Foramen

Large, triangular in shape.

3. Bony Structures

The pedicles are short and project posterolaterally. They are attached to the body midway between its upper and lower borders, so that the superior vertebral notch is as deep as the inferior.

The laminae are long, narrow, and thinner above than below.  They curve posteromedially.

The spinous process is short and bifid (to allow ligamentum nuchae to run through). Because the spinous processes are so short, certain superficial muscles (the trapezius and splenius capitis) attach to the nuchal ligament rather than directly to the vertebrae; the nuchal ligament itself attaching to the spinous processes of C2-C7 and to the posterior tubercle of the atlas.

The superior and inferior articular processes of cervical vertebrae have fused on either or both sides to form articular pillars, columns of bone that project laterally from the junction of the pedicle and lamina.

The articular facets are flat and of an oval form:

the superior face backward, upward, and slightly medially.

the inferior face forward, downward, and slightly laterally.

The transverse processes are short and house the foramen transversarium, which, in the upper six vertebrae, gives passage to the vertebral artery and vein, as well as a plexus of sympathetic nerves. Each process consists of an anterior and a posterior part. These two parts are joined, outside the foramen, by a bar of bone that exhibits a deep sulcus on its upper surface for the passage of the corresponding spinal nerve.

The anterior portion is the homologue of the rib in the thoracic region, and is therefore named the costal process or costal element. It arises from the side of the body, is directed laterally in front of the foramen, and ends in a tubercle, the anterior tubercle.

The posterior part, the true transverse process, springs from the vertebral arch behind the foramen, and is directed forward and laterally; it ends in a flattened vertical tubercle, the posterior tubercle.

Articulations

  1. Atlanto-occipital joint: It is a synovial joint, formed between the atlas (C1) and occipital bone.

Muscule and Ligament Attachments

Muscle attachments:

  1. Lumbar muscles
  2. Thoracic muscles
  3. Back muscles

Ligament attachments:

  1. Ligamenta flava
  2. Interspinous ligaments
  3. Nuchal ligament
  4. Supraspinous ligament

References

    1. The Cervical Spine — Teachmeanatomy.info
    2. Anatomy, Head and Neck, Cervical Vertebrae — Ncbi.nlm.nih.gov
    3. Cervical spine — Kenhub.com
    4. Cervical Vertebrae — Innerbody.com
    5. Cervical Vertebra — Sciencedirect.com

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