Surface Anatomy and Other Landmarks

  1. Laryngeal prominence (Adam's apple) in the midline formed by the thyroid cartilage at approximately C4.
  2. Inferiorly the ring of the cricoid cartilage may be palpated at C6.
  3. 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 bilaterally between ramus of the mandible and mastoid process.
  4. The hyoid bone: Its body is at the level of C3. It has lesser and greater horns bilaterally.
  5. The thyroid cartilage lies at the levels of C4 and C5. The laryngeal prominence is Adam's apple in the male. The thyroid cartilage is composed of 2 lateral laminae with superior and inferior horns. The inferior horns articulate with the cricoid cartilage.
  6. The cricoid cartilage is at C6. The upper end of the trachea is palpable in the midline from the cricoid cartilage to the superior border of the manubrium.
  7. The thyrohyoid membrane is pierced by the internal laryngeal nerve and vessels.
  8. The cricothyroid membrane may be used for a high tracheostomy.

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

Craniovertebral Joints

Clinical note: Tear of cruciate ligament of atlas can allow dens to be driven into spinal cord (resulting in quadriplegia) or medulla (resulting in death).

2. Alar ligament: extends laterally from dens to occipital bone; prevents excessive rotation of head.

3. Tectorial Membrane : extension of posterior longitudinal ligament of spinal column - extends from axis to occipital bone, posterior to cruciate ligament.

4. Anterior atlanto-occipital membrane:= extension of anterior longitudinal ligament - extends from atlas to occipital bone