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%).
Spinal Nerve Cross-Section. Spinal nerves are the peripheral nerves that connect the spinal cord to the diverse tissues of the body. Thirty-one pairs of spinal nerves extend from the spinal cord in the neck and back to supply the skin, muscles, and organs of the neck, trunk, and limbs. The 31 pairs of spinal nerves are named for the region of the vertebral column from which they exit the spinal cord.