Surface Anatomy and Other Landmarks
(Adam's apple) in the midline formed by the thyroid cartilage at approximately
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 bilaterally between ramus of the mandible
and mastoid process.
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 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.
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.
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 tracheotomy is at
tracheal cartilages 2-4 (below cricoid cartilage and isthmus of the thyroid
- Atlanto-occipital joint: joint between atlas
(vertebra C1) and occipital bone; movements - flexion - extension of the neck
(nodding the head in "yes" movement).
- Atlanto-axial joint: joint between atlas (C1)
and axis (C2); movement: lateral rotation of atlas on axis (shaking head in
- Ligaments of joint - stabilize joints and protect
medulla and spinal cord; some prevent excessive movement; some are extensions
of ligaments of spinal column
1. Cruciate (cross) ligament - composed of
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).
- Transverse ligament of atlas: transverse band
within vertebral canal which is attached to inner side of atlas; holds
dens of axis against inner aspect of anterior arch of atlas
- Superior and inferior bands: upper and lower
extensions from transverse ligament of atlas to occipital bone superiorly
and to body of the axis inferiorly.
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