The last 4 cranial nerves keep the skull close together, the glossopharyngeal, vagus and accessory via the jugular foramen and the hypoglossal nerve via the hypoglossal canal. The last 4 cranial nerves are the nerves of the neck and closely related to every other, therefore described collectively.
- In the beginning, the cranial root of the accessory nerve joins the vagus nerve and is spread via them, where they are located between the internal jugular vein and the internal carotid artery. Afterward, the glossopharyngeal nerve enters forward across the internal carotid artery and after that deep to the external carotid artery.
- The spinal accessory nerve enters backwards across the internal jugular vein and the vagus nerve enters straight down in the deeper plane between the internal jugular vein and the internal carotid artery.
- The hypoglossal nerve is medial to others, arch round behind the vagus nerve and after that enters forward, superficial to the vagus nerve, internal carotid and external carotid arteries.
- The close association of the past 4 cranial nerves can be well recognized by examining the features of the base of the skull around the jugular foramen.
- The jugular foramen lies in front of the jugular process of the occipital bone. The jugular fossa is a bony depression between the jugular foramen and base of the skull.