What is the 11th cranial nerve?

What is the 11th cranial nerve?

Spinal Accessory Nerve
The Spinal Accessory Nerve (SAN) or Cranial Nerve 11 is termed a cranial nerve as it was originally believed to originate in the brain. It has both a cranial and a spinal part, though debate still rages regarding if the cranial part is really a part of the SAN or part of the vagus nerve.

What cranial nerve is spinal accessory?

cranial nerve XI
The accessory nerve, also known as the eleventh cranial nerve, cranial nerve XI, or simply CN XI, is a cranial nerve that supplies the sternocleidomastoid and trapezius muscles.

What foramen does the accessory nerve pass through?

The accessory or spinal nerve has a double origin but always comes out of the jugular foramen. The jugular foramen develops embryologically from the otic capsule and the baseplate. Its spinal portion comes from a series of roots starting at C6-C7 and traveling cranially to enter in the foramen magnum.

Where is cranial nerve 11?

The spinal accessory nerve innervates two muscles – the sternocleidomastoid and trapezius. Attachments – Runs from the mastoid process of the temporal bone to the manubrium (sternal head) and the medial third of the clavicle (clavicular head).

What is 8th cranial nerve?

The vestibulocochlear nerve, also known as cranial nerve eight (CN VIII), consists of the vestibular and cochlear nerves. Each nerve has distinct nuclei within the brainstem.

Where does the accessory nerve originate?

The primary function of the accessory nerves (XI) is motor, to the muscles of the neck and upper back. These nerves originate in the motor nuclei of the spinal cord and medulla. They pass through the jugular foramina, between the occipital and temporal bones.

Where is the jugular foramen?

The two jugular foramina exist at the base of the skull lateral to the foramen magnum. Importantly the internal jugular veins, which drain blood from the brain and intracranial tissues, make their way out of the cranium and terminate at the subclavian veins and ultimately join the brachiocephalic vein.

What are 31 spinal nerves?

In humans there are 31 pairs: 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 1 coccygeal. Each pair connects the spinal cord with a specific region of the body. Near the spinal cord each spinal nerve branches into two roots.

What are the 3 main types of nerves?

There are three types of nerves in the body:

  • Autonomic nerves. These nerves control the involuntary or partially voluntary activities of your body, including heart rate, blood pressure, digestion, and temperature regulation.
  • Motor nerves.
  • Sensory nerves.

How are the 12 cranial nerves tested?

The 12th CN is tested by having the patient stick out their tongue and move it side to side. Further strength testing can be done by having the patient push the tongue against a tongue blade. Inspect the tongue for atrophy and fasciculations.

  • August 28, 2022