Cranial Nerves Flashcards
What CN are above the pons?
In the pons?
In the medulla?
What CN nuclei are medial?
I, II, III, IV
V, VI, VII, VIII
IX, X, XI, XII
III, IV, VI, XII
What CN is the olfactory N?
Fx?
What is the pathway of the olfactory N?
Where does it synapse?
What is an injury of the olfactory N called and how can it be damaged?
Do its afferent fibers go to the thalamus?
CN I; sensory
Smell (special sensory)
Cribriform plate of the ethmoid bone
Olfactory bulb -> piriform cortex
Anosmia; trauma, skull fracture infections, tumors
No
What CN is the optic N?
Fx?
What is the pathway of the optic N?
Arises from what?
CN II; sensory
Sight (special sensory)
Optic canal of sphenoid bone
Diencephalon
What are the three cranial nerves that innervate the ocular muscles?
What hole do these three nerves travel through?
Oculomotor N (CN III)
Trochlear N (CN IV)
Abducent N (CN VI)
Superior orbital fissure
Name the muscle with the somatic motor (efferent fiber) fx of the eye:
Moves eye up
Moves eye medial
Moves eye inferior
Moves eye superior rotation
Elevates eyelid
These fx are innervated by the _____. What CN is this?
Superior rectus m
Medial rectus m
Inferior rectus m
Inferior oblique m
Levator palpebrae
Nucleus of oculomotor N; CN III; motor
The ____ nucleus is responsible for the parasympathetic motor (visceral efferent) innervation of the oculomotor nerve. What are its two fx?
Visceral oculomotor nucleus
Sphincter pupillae -> pupillary constriction
Ciliary M -> near vision
In oculomotor N (CN III) palsy causes a ____ and ____ gaze, ____ pupil, and eyelid has to be ____ due to ptosis.
Downward and outward; dilated; manually elevated
What CN is the trochlear N?
What is its fx?
What muscle does it innervate and what is the fx of this muscle?
What does trochlear N palsy cause?
CN IV; motor
Eye movement (somatic motor)
Superior oblique m; turned eye down/in (read/stairs)
Strabismus (crossed eye), diplopia (double vision), eye tilted outward, unable to look down/in therefore the head is tilted away from the affected side to compensate
What CN is the abducens?
What is the fx?
And what muscle does it innervate?
What does abducens palsy cause?
CN VI; motor
Eye movement (somatic motor)
Lateral rectus m
Diplopia, can’t laterally move (look out) of affected eye
What CN is the trigeminal N?
What are the three divisions and what ganglion do they arise from?
What is the sensory fx and what division?
What is the motor fx and what division?
What reflex is the trigeminal N a part of and what division supplies this sensory input?
CN V; both sensory and motor
Ophthalmic (V1), maxillary (V2), mandibular (V3); trigeminal ganglion
Touch/pain/temperature to face -> V1, V2, V3
Muscles of mastication -> V3
Corneal reflex; V1
The ophthalmic (V1) division of the trigeminal N has what four branches?
What are smaller branches off two of the original branches?
Lacrimal
Frontal: supratrochlear, supraorbital N from frontal air sinus
Nasociliary: long and short ciliary, infratrochlear, ethmoidal (anterior with internal and external nasal), posterior
Meningeal branch: from tentorium cerebelli
What openings do the branches of the maxillary (V2) division of the trigeminal nerve enter and exit?
What are the six branches of the maxillary division?
Enter through foramen rotundum and exit through infraorbital foramen into maxillary region
Zygomatic: zygomaticotemporal, zygomaticofacial
Infraorbital: external nasal, superior labial
Superior alveolar: anterior, middle, posterior
Nasociliary
Palatine: orbital, greater and lesser palatine, posterior superior nasal, pharyngeal
Meningeal: anterior cranial fossa, middle cranial fossa
What are the sensory branches of the mandibular (V3) division of the trigeminal N?
Motor branches?
Buccal Lingual Inferior alveolar Auriculotemporal Meningeal
Medial ptergoid Lateral pterygoid Masseteric Deep temporal Mylohyoid
What does trigeminal palsy cause?
What are the symptoms of trigeminal neuralgia?
Numb face (sensory), weak jaw (motor) -> deviates to AFFECTED side (unopposed action of normal side)
Recurrent sudden sharp pain, tic douloureux (painful tic), wincing
What nerves induces the corneal reflex?
Input of senses by ____ nerve, transmitted to ____ nerve causing ____.
V1 of CN V
VII (bilaterally)
Eyes to blink