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What cranial nerve motor fibers to sternocleidomastoid and trapezius?
DebbyUnderwoodKurtz
The sternocleidomastoid and trapezius muscles are controlled by the accessory cranial nerve. Some call it cranial nerve XI.
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∙ 9y ago
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What cranial nerve is used when rotating the head?
The spinal accessory nerve, or cranial nerve XI (eleven), is a purely motor nerve which innervates the trapezius and sternocleidomastoid muscles. The sternocleidomastoid muscles are used to turn the head. The Accessory nerve also provides somatic motor fibers to muscles of the soft palate, pharynx, and larynx (spinal and medullary fibers respectively.)
What is the cranial nerves containing all or mostly motor fibers are?
Olfactory
What do the mixed cranial nerves containing both motor and sensory fibers include?
Olfactory
Which cranial nerve is attached to the cerebrum?
The cranial nerves that are attached to the medulla oblongata are the glossopharyngeal, vagus, accessory and hypoglossal nerves. The glossopharyngeal nerve is the ninth cranial nerve that causes the tongue, throat, and parotid gland to function properly. The vagus nerve is the tenth cranial nerve which helps with motor production, mainly regarding the process of voice production. The accessory nerve is the eleventh cranial muscle whose only function is motor function, mainly regarding the trapezius and sternocledomastoid muscles. Lastly, the hypoglossal nerve is the twelfth cranial nerve which helps in the proper functioning of the muscles under the tongue.
Who protects the spinal cords?
In anatomy, the accessory nerve is a nerve that controls specific muscles of the neck. As a part of it was formerly believed to originate in the brain, it is considered a cranial nerve. Based on its location relative to other such nerves, it is designated the eleventh of twelve cranial nerves, and is thus abbreviated CN XI. Although anatomists typically refer to the accessory nerve in singular, there are in reality two accessory nerves, one on each side of the body.Traditional descriptions of the accessory nerve divide it into two parts: a spinal part and a cranial part.[1] But because the cranial component rapidly joins the vagus nerve and serves the same function as other vagal nerve fibers, modern descriptions often consider the cranial component part of the vagus nerve and not part of the accessory nerve proper.[2] Thus in contemporary discussions of the accessory nerve, the common practice is to dismiss the cranial part altogether, referring to the accessory nerve specifically as the spinal accessory nerve.The spinal accessory nerve provides motor innervation from the central nervous system to two muscles of the neck: the sternocleidomastoid muscle and the trapezius muscle. The sternocleidomastoid muscle tilts and rotates the head, while the trapezius muscle has several actions on the scapula, including shoulder elevation and adduction of the scapula.Range of motion and strength testing of the neck and shoulders can be measured during a neurological examination to assess function of the spinal accessory nerve. Limited range of motion or poor muscle strength are suggestive of damage to the spinal accessory nerve, which can result from a variety of causes. Injury to the spinal accessory nerve is most commonly caused by medical procedures that involve the head and neck.[3]
Which cranial nerve is not purely motor?
IX
What other cranial nerves contain sensory fibers?
The listed cranial nerves provide both sensory and motor innervation:Trigeminal nerve (CN V)Facial nerve (CN VII)Glossopharyngeal nerve (CN IX)Vagus nerve (CN X)
Are cranial nerves motor or sensory?
sensory nerve
Is the optic nerve a sensory or motor nerve?
The optic nerve is a cranial nerve (CN II) that sends special somatic afferent (sensory) fibers to the lateral geniculate of the thalamus. Here, they synapse and continue via optic radiations to the primary visual cortex of the brain. The motor portion of the eye is controlled by cranial nerves as well only they are: Oculomotor (CN III), Trochlear (CN IV), and Abducens (CN VI); there is also some sympathetic innervation (not from cranial nerves) that cause pupillary dialation.
What is a motor unit is made up of?
Motor neurons and the muscle fibers they transmit signals toA motor unit is a collection of muscle fibers that contract as a single functional unit when stimulated by an impulse from a motor neuron. The actual size can vary greatly, from many large muscle fibers in the quadriceps muscle group per motor unit to just a few muscle fibers in the muscles of the fingers per motor unit.
What cranial nerves are involved in tooth ache in upper jaw?
The cranial nerve would be the 5th one (V), the Trigeminal. This nerve is responsible for conduction sensory impulses from the skin of the face and mucosa of the nose and mouth. Also, it contains motor fibers that activate the chewing muscles.
How many pairs are of the cranial nerves?
There are 12 pairs of cranial nerves that are part of the PNS. These nerves are sensory, mixed and mostly motor.
