Term
| CN1 - The Olfactory Nerve |
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Definition
Special sensory
Supplies sense of smell
Passes throughthe cribiform plate of the ethmoid.
CLINICAL CORRELATES: a broken nose can damage a) the sense of smell and b) the meninges (which can cause a loss of CSF and subsequent meningitis). |
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Term
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Definition
Special sensory
Transmits information from eye to brain
Passes through the optic foramen
The Central Retinal Artery and Vein pass through the nerve.
CLINICAL CORRELATES: an increase in CSF pressure is transmitted to the optic disk and compresses the optic nerve, causing blurring on the margins of the optic disk, a condition known as papilledema |
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Term
| CN3 - The Occulomotor Nerve |
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Definition
Mixed nerve
Has sensory control of the proprioceptors of the eye
Has motor control of the eye lids, extrinsic muscles of the eye, iris sphincter and ciliary muscles.
CLINICAL CORRELATES: conditions such as cavernous sinus thrombosis and aneurysms of the posterior communicating artery can compress the nerve, which will lead to a palsy that can present with diplopia, ptosis, dilated pupil, absent pupillary reflex and absent accomodation reflex |
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Term
| CN4 - The Trochlear Nerve |
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Definition
Motor nerve
Supplies finction to the superior oblique muscle (which is responsible for the downward movement of the eye)
CLINICAL CORRELATES: lesion causes diplopia |
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Term
| CN5 - The Trigeminal Nerve |
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Definition
Mixed nerve
Has three branches...
1. Opthalmic - sensory innervation to skin of forehead, upper eyelid, part of the nose and the cornea
2. Maxillary - sensory innervation to the skin of the temple, cheek rest of nose and upper lip, the muscous membranes of the nose, the palate and upper dental arcade
3. Mandibular - sensory to the skin of the lower lip, chin, skin anterior to the ear and up to the scalp, the lower dental arcade and the anterior 2/3 of the tongue. Also motor supply to the muscles of mastication.
CLINICAL CORRELATES: dysfunction of the trigeminal nerve causes paralysis of the muscles of mastication and a shap, intense, facial pain. |
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