Antrochoanal polyps arise from the maxillary sinuses and are the much less common; ethmoidal polyps arise from the ethmoidal sinuses. Symptoms of polyps include nasal congestion, sinusitis, anosmia (loss of smell), and secondary infection leading to headache.
Relationship of internal jugular vein to the spinal accessory nerve (SAN). Spinal accessory nerve (SAN) posterior to the internal jugular vein. As the nerve approaches the sternocleidomastoid muscle (SCM), it may perforate the cleidomastoid portion of the SCM (80%) or run posterior to it (20%).
Accessory nerve (XI). The accessory nerve is part of the group of cranial nerves responsible for innervation of structures derived from the branchial arches. It is also part of a group together with the glossopharyngeal and vagus nerves that passes through the jugular foramen which is termed the vagus group.