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Osteology:

The temporal bone, zygomatic arches, occipital bone, mandible, cervical vertebrae, scapula clavicles, manubrium, and hyoid bone form the skeleton of the neck.

Cervical Vertebrae: C1-C7

Enclosed within the vertebral canal is the spinal cord and the meninges
Foramen transversarium: Within transverse processes containing the vertebral vessels*

C1(a): Atlas – Carrier of the Skull
- Lacks a spinous process and body
- Consists of two lateral masses connected by anterior and posterior arches with concave articular facets receiving the occipital condyles superiorly
- Anteriorly, possesses a facet for articulating with the Dens on the anterior arch
- Superiorly, posterior to the condylar fossa, it possesses a groove where the vertebral artery, vein and c1 travel
- Transverse Processes can be palpated posterior to the ramus of the mandible

C2(b): Axis – Often considered the body of C1
- Dens: Peglike odontoid process projecting superiorly from body that forms the pivot around which the Atlas rotates

C3, C4, C5, & C6 Characteristics:

Vertebral body

small and longer from side to side than anteroposteriorly
superior surface is concave forming the uncinate processes laterally
inferior surface is convex
can be used as a landmark for hyoid (C3), thyroid cartilage and bifurcation of the common carotid artery (C4), cricoid cartilage (C6)

Vertebral foramen is large and triangular

C7: Vertebrae Prominens

Long spinous process visible through skin
Large transverse processes
*Foramina transversaria are small and only transmits vertebral vein

Hyoid Bone

Mobile, C-Shaped bone lying in the anterior part of the neck at the level of C3 in the angle between the mandible and the thyroid cartilage.
Suspended by muscles that connect to the mandible, styloid processes, thyroid cartilage, manubrium of the sternum, and the scapulae
Does not articulate with any other bone – Suspended from the styloid processes of the temporal bones by the stylohyoid ligaments and is firmly bound to the thyroid cartilage by the thyrohyoid membrane
Functionally serves as an attachment for the deep investing fascia, anterior neck muscles and keeps the airway open

Surface Anatomy and Other Landmarks

Laryngeal prominence (Adam's apple) in the midline formed by the thyroid cartilage at approximately C4.

Inferiorly the ring of the cricoid cartilage may be palpated at C6.

The tips of the transverse processes of C1 are more prominent than those of other cervical vertebrae and can be palpated in the parotid space.

The hyoid bone: Its body is at the level of C3. It has lesser and greater horns bilaterally.

The thyroid cartilage lies at the levels of C4 and C5. The laryngeal prominence is Adam's apple. The thyroid cartilage is composed of 2 lateral laminae with superior and inferior horns. The inferior horns articulate with the cricoid cartilage.

The cricoid cartilage at C6. The upper end of the trachea is palpable in the midline from the cricoid cartilage to the superior border of the manubrium.

The thyrohyoid membrane is pierced by the internal laryngeal nerve and vessels.

The cricothyroid membrane may be used for a high tracheostomy.

*The preferred site of tracheostomy is at tracheal cartilages 2-4 (below cricoid cartilage and isthmus of the thyroid gland).

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