Cranial nerves Health Dictionary

Cranial Nerves: From 3 Different Sources


Twelve pairs of nerves that emerge directly from the underside of the brain. Each of the nerves has a number as well as a name. The numbers indicate the sequence in which the nerves emerge from the brain.

The main function of some cranial nerves is to deliver sensory information from the ears, nose, and eyes to the brain.

These are the vestibulocochlear nerve (hearing and balance), olfactory nerve (smell), and optic nerve (vision). Other cranial nerves carry impulses that move muscles of the head and neck area. These are the oculomotor, trochlear, and abducent nerves (movements of the eye), spinal accessory nerve (head and shoulder movements), and hypoglossal nerve (tongue movements).

Some cranial nerves have both sensory and motor functions. These are the facial nerve (facial expressions, taste, and the secretion of saliva and tears) trigeminal nerve (facial sensation and jaw movements) and glossopharyngeal nerve (taste and swallowing movements). The vagus nerve has branches to all the main digestive organs, the heart, and the lungs, and is a major component of the parasympathetic nervous system, which is concerned with maintaining the body’s automatic functions.

All but 2 of the cranial nerve pairs connect with nuclei in the brainstem (the olfactory and optic nerves link directly with parts of the cerebrum). The nerves emerge through openings in the cranium; many then soon divide into branches.

Health Source: BMA Medical Dictionary
Author: The British Medical Association
Cranial nerves are those arising from the BRAIN.
Health Source: Medical Dictionary
Author: Health Dictionary
the 12 pairs of nerves that arise directly from the brain and leave the skull through separate apertures; they are conventionally given Roman numbers, as follows: I *olfactory; II *optic; III *oculomotor; IV *trochlear; V *trigeminal; VI *abducens; VII *facial; VIII *vestibulocochlear; IX *glossopharyngeal; X *vagus; XI *accessory; XII *hypoglossal. Compare spinal nerves.
Health Source: Oxford | Concise Colour Medical Dictionary
Author: Jonathan Law, Elizabeth Martin

Sacral Nerves

These are five pairs of CNS nerves that exit through the sacral foramen and sacral hiatus, and bring information in and out of the spinal cord. Much of their function relates to the sciatic nerve, and they bring information in from the skin sensory zones (dermatomes) of the heel, back of the legs, buttocks, and the pelvic floor.... sacral nerves

Spinal Nerves

A set of 31 pairs of nerves that connect to the spinal cord. Spinal nerves emerge in 2 rows from either side of the spinal cord and leave the spine through gaps between adjacent vertebrae. The nerves then branch out to supply all parts of the trunk, arms, and legs with sensory and motor nerve fibres.

Disc prolapse may lead to pressure on a spinal nerve, causing pain. Injury to a nerve may lead to loss of sensation or movement in the area supplied by the nerve. (See also nerve injury; neuropathy.)... spinal nerves

Nerves Twelve Nerves Come Off The Brain:

I. Olfactory, to the nose (smell).

II. Optic, to the eye (sight).

III. Oculomotor

Trochlear, to eye-muscles.

Abducent

VI. Trigeminal, to skin of face.

VII. Facial, to muscles of face.

VIII. Vestibulocochlear, to ear (hearing and balancing).

IX. Glossopharyngeal, to tongue (taste).

X. Vagus, to heart, larynx, lungs, and stomach.

XI. Spinal accessory, to muscles in neck.

XII. Hypoglossal, to muscles of tongue.... nerves twelve nerves come off the brain:

Nerves, Injuries To

These have several causes. Continued or repeated severe pressure may damage a nerve seriously, as in the case of a crutch pressing into the armpit and causing drop-wrist. Bruising due to a blow which drives a super?cially placed nerve against a bone may damage, say, the radial nerve behind the upper arm. A wound may sever nerves, along with other structures; this accident is specially liable to occur to the ulnar nerve in front of the wrist when a person accidentally puts a hand and arm through a pane of glass.

Symptoms When a sensory nerve is injured or diseased, sensation is immediately more or less impaired in the part supplied by the nerve. Ulceration or death of the tissue supplied by the defective nerve may occur. When the nerve in question is a motor one, the muscles governed through it are instantly paralysed. In the latter case, the portion of nerve beyond the injury degenerates and the muscles gradually waste, losing their power of contraction in response to electrical applications. Finally, deformities result and the joints become ?xed. This is particularly noticeable when the ulnar nerve is injured, the hand and ?ngers taking up a claw-like position. The skin may also be affected.

Treatment Damaged or severed (peripheral) nerve ?bres should be sewn together, using microsurgery. Careful realignment of the nerve endings gives the ?bres an excellent chance of regenerating along the right channels. Full recovery is rare but, with regular physiotherapy to keep paralysed muscles in good shape and to prevent their shortening, the patient can expect to obtain a reasonable return of function after a few weeks, with improvement continuing over several months.... nerves, injuries to

Olfactory Nerves

The nerves of SMELL. Each nerve detects smell by means of hair-like receptors positioned in the mucous membrane lining the roof of the nasal cavity (see NOSE).... olfactory nerves

Tea For Nerves

Nerve damage can include neuropathy or neuritis, which can be caused by diabetes, nerve injury, autoimmune disease, viral infections, muscle spasms or vitamin deficiencies. Traditional medicine found a lot of treatments for nerve damage, but alternative medicine fans think that you don’t need to take a lot of pills for something that can be treated with just a cup of tea. How a Tea for Nerves Works A Tea for Nerves’ main purpose is to nourish your nervous system and induce a state of relaxation to all your nervous cells. Also, these teas can reconstruct the damaged tissue and make your body heal all affected areas. In order to be useful, a Tea for Nerves needs to contain tannins, volatile oils and minerals (manganese, magnesium, iron, preferably). Efficient Tea for Nerves When choosing a Tea for Nerves, remember that it must be both one hundred percent safe and very efficient. If you don’t know which teas to choose from, here’s a list to help you out: - Saint John’s Wort Tea – is useful for sciatica and it can bring relief to patients suffering from depression and spinal nerves damages. Take only a cup per day and avoid it at all costs if you’re on antidepressants. Also, if you’re pregnant, talk to your doctor before starting a treatment based on Saint John’s Wort Tea. - Skullcap Tea – treats a number of affections such as inflammation, arteriosclerosis, high cholesterol and epilepsy thanks to its active constituents: antioxidant flavonoids, which can repair the nervous damages and baicalin (has anti-spastic and nerve-relaxant properties). Don’t take more than 2 cups per day for a short amount of time and don’t combine it with anti-depressants and sedatives. Basil Tea – this Tea for Nerves has many medical uses and not only that it can repair the nervous ailments, but it’s also a great energy and health enhancer. You can also use it to treat asthenia, anemia, loss of appetite and digestive tract problems. Drink one or two cups per day for a short amount of time and enjoy the health benefits! Tea for Nerves Side Effects When taken properly, these teas are generally safe. However, make sure you don’t exceed the number of cups recommended per day or you’ll get diarrhea, constipation, nausea, headaches or skin rashes. If you’ve been taking one of these teas for a while and you’re experiencing some unusual reactions, talk to your doctor as soon as possible! Don’t take a Tea for Nerves if you’re pregnant, breastfeeding, on blood thinners, anticoagulants or preparing for a major surgery (these teas contains substances that may interfere with your anesthetic). The same advice for children: there are no studies to examine the treatment’s effect on them. If your doctor says it’s ok to try a Tea for Nerves, choose one that fits best your needs and enjoy its wonderful health benefits!... tea for nerves

Episodic Cranial Sensory Shock

see exploding head syndrome.... episodic cranial sensory shock

Pilomotor Nerves

sympathetic nerves that supply muscle fibres in the skin, around the roots of hairs. Activity of the sympathetic nervous system causes the muscles to contract, raising the hairs and giving the *gooseflesh effect of fear or cold.... pilomotor nerves

Vasomotor Nerves

Small nerve ?bres that lie upon the walls of blood vessels and connect the muscle ?bres of their middle coat with the NERVOUS SYSTEM. Through these nerves the blood vessels are retained in a state of moderate contraction. There are vasodilator nerves, through which are transmitted impulses that dilate the vessels, and, in the case of the skin vessels, produce the condition of blushing; there are also vasoconstrictor nerves which transmit impulses that constrict, or narrow, the blood vessels – as occurs on exposure to cold (see HYPOTHERMIA). Various drugs produce dilatation or contraction of the blood vessels, and several of the substances produced by ENDOCRINE GLANDS in the body have these effects: for example, ADRENALINE.... vasomotor nerves

Splanchnic Nerves

the series of nerves in the sympathetic system that are distributed to the blood vessels and viscera, passing forwards and downwards from the chain of sympathetic ganglia near the spinal cord to enter the abdomen and branch profusely.... splanchnic nerves



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