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Bùi Thị Kim Oanh đang tìm kiếm từ khóa What are the cranial nerves and their functions? được Cập Nhật vào lúc : 2022-11-29 07:28:06 . Với phương châm chia sẻ Thủ Thuật về trong nội dung bài viết một cách Chi Tiết 2022. Nếu sau khi đọc nội dung bài viết vẫn ko hiểu thì hoàn toàn có thể lại Comments ở cuối bài để Mình lý giải và hướng dẫn lại nha.Description[edit | edit source]
Nội dung chính Show - Description[edit | edit source]Function[edit |
edit source]Dysfunction of Cranial
nerves[edit | edit source]Clinical Relevance and Assessment
[8][9][edit |
edit source]See also[edit | edit source]References[edit | edit source]What are the 12 cranial nerves and their function?What are the 12 cranial nerves in order?What are the 12 cranial nerves and functions BYJU's?What are the 12 cranial nerves and functions Wikipedia?
Twelve pairs of nerves (the cranial nerves) lead directly from the brain to various parts of the head, neck, and trunk. Some of the cranial nerves are involved in the special senses (such as seeing, hearing, and taste), and others control muscles in the face or regulate glands. The nerves are named and numbered (according to their location, from the front of the brain to the back).
Image 1: Twelve pairs of cranial nerves emerge from the underside of the brain, pass through openings in the skull, and lead to parts of the head, neck, and trunk. The nerves are named and numbered, based on their location, from the front of the brain to the back. Thus, the olfactory nerve is the 1st cranial nerve, and the hypoglossal nerve is the 12th cranial nerve
Unlike spinal nerves whose roots are neural fibers from the spinal grey matter, cranial nerves are composed of the neural processes associated with distinct brainstem nuclei and cortical structures.[1]
The names of the cranial nerves (CN) are: CN I - Olfactory, CN II - Optic, CN III - Oculomotor, CN IV - Trochlear, CN V - Trigeminal, CN VI - Abducens, CN VII - Facial, CN VIII - Vestibulocochlear, CN IX - Glossopharyngeal, CN X - Vagus, CN XI - Accessory, and CN XII - Hypoglossal. [2] Link: Introduction to Neuroanatomy
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Function[edit | edit source]
The names of the cranial nerves sometimes correspond with their individual function. Some of the cranial nerves are purely sensory, others are purely motor, and the rest have both sensory and motor components.
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Smell (olfaction)
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CN II - Optic
Vision
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CN III - Oculomotor
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Innervates the inferior oblique muscle and medial, inferior, and superior rectus muscles of the eye (move the eye); levator palpebrae superioris muscle (elevate eyelid)
Innervates the sphincter pupillae muscle (constricts the pupil), and the ciliary muscle (accomodate the eye for near vision)
CN IV - Trochlear
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Innervate the superior oblique eye muscle (moves the eye inferiorly and laterally)
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CN V - Trigeminal
Conducts touch, temperature and pain sensation from the face, nose, mouth, nasal and oral mucosa, anterior two-thirds of tongue, and anterior scalp; part of auricle of the ear
Innervate the muscles of mastication, mylohyoid, digastric (anterior belly), tensor veli palatini, and tensor tympani
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CN VI - Abducens
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Innervate the lateral rectus muscle of eye (abducts the eye)
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CN VII - Facial
Taste from anterior two-thirds of tongue
Innervate muscles of facial expression, digastric (posterior belly), stylohyoid and stapedius muscle
Increase secretion from the lacrimal (tear glands) and nasal mucosal glands; submandibular and sublingual
salivary glands
CN VIII - Vestibulocochlear
Hearing (cochlear branch); linear and angular acceleration, or head position in space/equilibrium
(vestibular branch)
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CN IX - Glossopharyngeal
Touch and taste from the posterior 1/3 of the tongue; visceral sensory from the carotid sinus and bodies
Innervate the pharyngeal muscle Stylopharyngeus
Increase secretion from the parotid salivary gland
CN X - Vagus
Visceral sensation (excluding pain) from heart, lungs, abdominal organs, bronchi, trachea, larynx, pharynx, gastrointestinal
tract to level of descending colon.
General sensation from the external acoustic meatus, eardrum, and pharynx
Innervates smooth muscles and glands of the heart, lungs larynx, trachea, and most abdominal organs
CN XI - Accessory
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Innervates the trapezius and sternocleidomastoid muscle
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CN XII - Hypoglossal
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Innervates intrinsic and extrinsic tongue muscles
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[embed]https://www.youtube.com/watch?v=FtJtYMRVw7A[/embed]
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Dysfunction of Cranial nerves[edit | edit source]
Dysfunction of certain cranial nerves may affect the eye, pupil, optic nerve, or extraocular muscles and their nerves; thus, they can be considered cranial nerve disorders, neuro-ophthalmologic disorders, or both.
Cranial nerve disorders can also involve dysfunction of smell, vision, chewing, facial sensation or expression, taste, hearing, balance, swallowing, phonation, head turning and shoulder elevation, or tongue movements (see table below). One or more cranial nerves may be affected.
These disorders can result from tumors, inflammation, trauma, systemic disorders, and degenerative or other processes, causing such symptoms as vision loss, diplopia, ptosis, pupillary abnormalities, periocular pain, facial pain, or headache[7].
Treatment of neuro-ophthalmologic and cranial disorders depends on the cause.
Clinical Relevance and Assessment [8][9][edit | edit source]
Cranial Nerve Integrity Cranial NerveExamination
Involvement
CN I - Olfactory
- Test sense of smell by closing the other nostril and using non-irritating odors like coffee, lemon oil, etc
- Inability to detect smells (Anosmia) = temporal lobe lesions
CN II - Optic
- Test visual acuity using a Snellen chart, test central and peripheral vision
- Blindness, impaired vision: far (myopia) and near (presbyopia)
CN II – Optic
CN III – Oculomotor
- Test pupil equality, size and shape
- Test pupil constriction by shining a light in the eye
- Absence of pupil constriction
- Unequal pupils (anisocoria)
- Horner’s syndrome
- CN III paralysis
CN III – Oculomotor
CN IV – Trochlear
CN VI - Abducens
- Test extraocular movements
- Observe eye position, presence of strabismus (loss of ocular alignment) or ptosis of eyelid
- Test pursuit eye movement without head movement
- Strabismus and impaired eye movement
- CN III: Ptosis, pupil dilation
- CN IV: Eye cannot look down when adducted
- CN VI: Eye pulled inward, eye cannot look out
CN V - Trigeminal
- Pain and light touch sensation of face (forehead, cheeks, jaw)
- Open and close jaw against resistance
- Test corneal and jaw jerk reflex
- Loss of facial sensation and numbness
- Loss of ipsilateral corneal reflex
- Weakness and wasting of mastication muscles
- Jaw deviation when opened to ipsilateral side
CN VII - Facial
- Test motor function of the facial muscles and look for asymmetry: raise eyebrows, frown, smile, close eyes tightly, puff cheeks, etc.
- Ipsilateral paralysis of facial muscles: unable to close eye, mouth corner droops, difficulty with speech articulation
= peripheral nerve injury (PNI) Bell’s Palsy (CN VII); or facial paralysis due to stroke
CN VIII - Vestibulocochlear
- Test balance
- Gaze instability with head rotations
- Test auditory acuity with a tuning fork placed in the middle on top of the head and check if the sound is equal or louder in one ear (Weber’s test)
- Vibrating tuning fork place on mastoid bone, then near the ear canal and note hearing acuity (Rinne’s test)
- Vertigo and disequilibrium
- Nystagmus
- Deafness, tinnitus and hearing loss
- Unilateral conductive loss
- Sensorineural loss: sound heard in good ear
- Conductive loss: sound heard through bone is longer or equal than air
- Sensorineural loss: sound heard longer through air
CN IX – Glossopharyngeal
CN X - Vagus
- Listen to voice quality
- Test for difficulty swallowing
- Let the patient say “ah” and observe the soft palate elevating and that the uvula remain in midline
- Examine the gag reflex
- Dysphonia
- Dysphagia
- With paralysis the palate does not elevate (lesion CN V), unilateral paralysis there is asymmetrical elevation
- Absent gag reflex (lesion CN IX, possibly X)
CN XI - Accessory
- Examine muscle bulk
- Test Trapezius and Sternocleidomastoid muscles against resistance
- Atrophy, fasciculations, weakness PNI: shoulder droops and unable to shrug ipsilateral shoulder
- Unable to turn the head to the contralateral side
CN XII - Hypoglossal
- Examine protruded tongue: rapid side-to-side movements
- Examine the tongue’s resting position
- Listen to the patient’s word articulations
- Movement impairment: deviation to weak side
- Atrophy or tongue fasciculations
- Dysartrhia (CN X or XII lesions)
See also[edit | edit source]
- Moebius SyndromeBell's PalsyTemporomandibular DisordersAcoustic NeuromaMigraine HeadacheRamsay Hunt SyndromeTrigeminal NeuralgiaCervicogenic HeadacheSturge-Weber SyndromeSynkinesisAccessory Nerve Cranial Nerve XIAbducens Nerve Cranial Nerve VI
References[edit | edit source]
↑ Sonne J, Lopez-Ojeda W. Neuroanatomy, cranial nerve. InStatPearls [Internet] 2022 Apr 3. StatPearls Publishing.↑ 2.0 2.1 McKinley M, O'Loughlin VD. Human Anatomy. 2nd ed. Tp New York: McGraw-Hill, 2008fckLRfckLRHill C. Practical guidelines for cystic fibrosis care. Edinburgh: Churchill Livingstone, 1998.↑ Image: Wikipedia, https://en.wikipedia.org/wiki/Trochlear_nerve (accessed 12 Oct 2022)↑ Butler A.B. Encyclopedia of the Human Brain, Four-Volume Set. Academic Press; 2002.↑ Fuller KS, Introduction to Central Nervous System Disorders. Goodman CC, Fuller KS. Pathology: implications for the physical therapist. Elsevier Health Sciences; 2014. p1371-1404↑ Youtube Video: MEDZCOOL - How to Remember the Cranial Nerves (Mnemonic) https://youtu.be/6ENCJkXJvio (accessed 12 Oct 2022)↑ MSD manauls Overview of Neuro-ophthalmologic and Cranial Nerve Disorders Available from: https://www.msdmanuals.com/professional/neurologic-disorders/neuro-ophthalmologic-and-cranial-nerve-disorders/overview-of-neuro-ophthalmologic-and-cranial-nerve-disorders (accessed 4.2.2022)↑ O'Sullivan SB, Neuromuscular Physical Therapy. In: O'Sullivan SB, Siegman RP. National Physical Therapy Examination Review & Study Guide. 19th edit. Evanston: TherapyEd, 2022. p121-184↑ Chui KK, Schmitz TJ. Examination in Sensory Function. In: Physical Rehabilitation. 6th Edit. Philadelphia: O’Sullivan SB, Schmitz TJ, Fulk GD F.A. Davis Company, 2014. P87-121What are the 12 cranial nerves and their function?
Table: Overview of the 12 cranial nerves (CNs).What are the 12 cranial nerves in order?
Olfactory nerve (CN I), optic nerve (CN II), oculomotor nerve (CN III), trochlear nerve (CN IV), trigeminal nerve (CN V), abducens nerve (CN VI), facial nerve (CN VII), vestibulocochlear nerve (CN VIII), glossopharyngeal nerve (CN IX), vagus nerve (CN X), accessory nerve (CN XI), and hypoglossal nerve (CN XII).What are the 12 cranial nerves and functions BYJU's?
There are 12 pairs of cranial nerves in the human body toàn thân. The olfactory nerve, optic nerve, facial nerve, oculomotor nerve, vagus nerve, hypoglossal, nerve, vestibulocochlear nerve, accessory nerve, trochlear nerve, glossopharyngeal nerve, trigeminal nerve and abducens nerve.What are the 12 cranial nerves and functions Wikipedia?
The nerves are: the olfactory nerve (I), the optic nerve (II), oculomotor nerve (III), trochlear nerve (IV), trigeminal nerve (V), abducens nerve (VI), facial nerve (VII), vestibulocochlear nerve (VIII), glossopharyngeal nerve (IX), vagus nerve (X), accessory nerve (XI), and the hypoglossal nerve (XII). Tải thêm tài liệu liên quan đến nội dung bài viết What are the cranial nerves and their functions?