What is the function of the spinal accessory nerve?

The spinal accessory nerve provides motor function to the sternocleidomastoid muscle, which extends the neck and the trapezius, as well as the upper back and shoulder. Dysfunction of the spinal accessory nerve can negatively affect the shoulder's performance.

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Subsequently, one may also ask, what does the spinal accessory nerve do?

The spinal component of the accessory nerve provides motor control of the sternocleidomastoid and trapezius muscles. The trapezius muscle controls the action of shrugging the shoulders, and the sternocleidomastoid the action of turning the head.

Subsequently, question is, what happens if the accessory nerve is damaged? The spinal accessory nerve originates in the brain and enables motion in the trapezius and sternomastoid muscles in the neck. A spinal accessory nerve injury can be caused by trauma or damage during surgery, resulting in shoulder pain, "winging" of the shoulder blades and weakness of the trapezius muscle.

Similarly one may ask, how do you find the spinal accessory nerve?

The main identification point of the nerve is in the posterior triangle, behind the posterior edge of the sternocleidomastoid muscle at Erb's point, which is defined by the exit of the greater auricular nerve from behind the sternocleidomastoid muscle.

Is spinal accessory nerve motor or sensory?

The Accessory Nerve (CN XI) The accessory nerve is the eleventh paired cranial nerve. It has a purely somatic motor function, innervating the sternocleidomastoid and trapezius muscles.

Related Question Answers

What does the accessory nerve innervate?

Sternocleidomastoid muscle Trapezius

Where does the accessory nerve originate from?

The spinal accessory nerve originates from the C1–C4 roots, ascending through the foramen magnum and then returning via the jugular foramen. The nerve first innervates the sternocleidomastoid muscle before running over the posterior cervical triangle to innervate the trapezius muscle.

What does the vagus nerve control?

The vagus nerve, the longest of the cranial nerves, controls your inner nerve center—the parasympathetic nervous system. And it oversees a vast range of crucial functions, communicating motor and sensory impulses to every organ in your body.

Where is the vagus nerve located?

The vagus nerve runs from the brain through the face and thorax to the abdomen. It is a mixed nerve that contains parasympathetic fibres. The vagus nerve has two sensory ganglia (masses of nerve tissue that transmit sensory impulses): the superior and the inferior ganglia.

Is cranial nerve 8 sensory or motor?

Table of cranial nerves

No.	Name	Sensory, motor, or both
V	Trigeminal	Both sensory and motor
VI	Abducens	Mainly motor
VII	Facial	Both sensory and motor
VIII	Vestibulocochlear In older texts: auditory, acoustic.	Mostly sensory

What does the trigeminal nerve do?

The trigeminal nerve (the fifth cranial nerve, or simply CN V) is a nerve responsible for sensation in the face and motor functions such as biting and chewing; it is the largest of the cranial nerves.

How do you remember the cranial nerves?

Mnemonics

1. O: olfactory nerve (CN I)
2. O: optic nerve (CN II)
3. O: oculomotor nerve (CN III)
4. T: trochlear nerve (CN IV)
5. T: trigeminal nerve(CN V)
6. A: abducens nerve (CN VI)
7. F: facial nerve (CN VII)
8. A: auditory (or vestibulocochlear) nerve (CN VIII)

How many spinal nerves are there?

Spinal nerve. Spinal nerve, in vertebrates, any one of many paired peripheral nerves that arise from the spinal cord. 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.

What is a nerve point?

Punctum nervosum, also known as Erb's point or the nerve point of the neck, is a point half way along the posterior border of the sternocleidomastoid muscle from which all cutaneous branches of the cervical plexus converge and become superficial.

What is the accessory nerve responsible for?

Accessory nerve. The accessory nerve is a cranial nerve that controls the movement of certain neck muscles. It is coiled in appearance. It is divided into spinal and cranial divisions, but its cranial part is often disregarded.

Where is the spinal accessory nerve particularly at risk of damage?

The spinal accessory nerve (SAN) extends from the brain, down the side of the neck and along the trapezius muscle. The SAN is highly prone to injury due to its long length and being shallow underneath the skin. SAN injuries are mostly caused by medical procedures and surgeries.

What would happen if there were nerve damage to the sternocleidomastoid?

Interruption of the nerve supply to the sternocleidomastoid muscle results in an asymmetric neckline, while weakness of the trapezius muscle can produce a drooping shoulder, winged scapula, and a weakness of forward elevation of the shoulder.

What are the symptoms of cranial nerve damage?

Cranial nerve disorders can cause a variety of symptoms, including:

• Intermittent attacks of excruciating facial pain.
• Vertigo (dizziness)
• Hearing loss.
• Weakness.
• Paralysis.
• Facial twitch.

What happens when the hypoglossal nerve is damaged?

Damage to the hypoglossal nerve causes paralysis of the tongue. Usually, one side of the tongue is affected, and when the person sticks out his or her tongue, it deviates or points toward the side that is damaged. Treatments for damage include tongue exercises, speech therapy, and, in rare cases, surgery.

How do you test vagus nerve?

To test the vagus nerve, a doctor may check the gag reflex. During this part of the examination, the doctor may use a soft cotton swab to tickle the back of the throat on both sides. This should cause the person to gag. If the person doesn't gag, this may be due to a problem with the vagus nerve.

What can cause a dropped shoulder?

The most common causes of radiculopathy are cervical disc herniation followed by cervical spondylosis. Compression of the cervical roots by muscle spasm has been proposed as the cause of dropped shoulder syndrome; this possibility is discussed herein.

What is a mixed nerve?

A mixed nerve is a nerve that contains both afferent and efferent nerves. Therefore, mixed nerves function to transmit both sensory and motor

What is trapezius palsy?

Trapezius palsy is an uncommon nerve condition in the shoulder that causes pain and weakness. It involves injury to the spinal accessory nerve at the neck or shoul- der. The spinal accessory nerve runs from the neck to the trapezius muscle. The scapula is the base from which the shoulder functions.

What is hypoglossal?

The hypoglossal nerve is the twelfth paired cranial nerve. Its name is derived from ancient Greek, 'hypo' meaning under, and 'glossal' meaning tongue. The nerve has a purely somatic motor function, innervating all the extrinsic and intrinsic muscles of the tongue (except the palatoglossus, innervated by vagus nerve).