Figure 4

Medial view of looping* of the cervical part of the right internal carotid artery (ICA) on sagittal cross section of the head and neck (upright position). 1 – optic nerve; 2 – cerebral part of ICA; 3 – cavernous part of ICA bulging wall of sphenoidal sinus (SS); 4 – mucosal lining of right wall of SS; 5 – basilar part of occipital bone; 6 – anterior border of foramen magnum; 7 – longus capitis; 8 – anterior arch of atlas; 9 – dens of axis; 10 – body of axis; 11 – intervertebral disk between C2 & C3 vertebrae; 12 – body of C3 vertebra; 13 – cervical part of spinal cord; 14 – internal jugular vein; 15 – superior laryngeal nerve; 16 – lingual artery; 17 – facial artery; 18 – root of tongue (lingual tonsil); 19 – dorsum of tongue; 20 – soft palate; 21 – posterior end of inferior nasal concha; 22 – posterior end of middle nasal concha; 23 – pharyngeal tonsil; 24 – pharyngeal recess; 25 – lateral wall of nasopharynx; 26 – pharyngeal opening of auditory tube; 27 – torus tubarius; ECA – external carotid artery