Cranial Nerves Flashcards
Which cranial nerves are purely sensory?
I, II VIII
Which cranial nerves are purely motor?
III, IV, VI, XI, XII
Which cranial nerves are mixed?
V, VII, IX, X
What are the 3 different motor columns in the brainstem for cranial nuclei organisation?
somatic, branchial, visceral (autonomic)
Which cranial nerves have somatic motor nuclei?
III, IV, VI, XII
Which cranial nerves have branchial motor nuclei?
V, VII, IX, X
What is the nucleus ambiguous?
the branchial motor nucleus to IX and X - located within the medulla behind the inferior olive - innervates stylopharyngeus and levator palati
Which cranial nerves have visceral motor nuclei?
III, VII, IX, X
What is the Edinger Westfal nucleus?
the visceral motor nucleus for CNIII - located in the midbrain
What is the superior salivatory nucleus?
the visceral motor nucleus for CNVII - located in the pons
What is the inferior salivatory nucleus?
the visceral motor nucleus for CNIX - located in the medulla
What is the dorsal motor nucleus of the vagus?
the visceral motor nucleus for CNX - located in the medulla
What are the 3 different sensory columns located in the brainstem for cranial nuclei organisation?
visceral sensory, somatic sensory, special sensory
Which cranial nerves have visceral sensory nuclei?
VII, IX, X
What is the nucleus solitarius?
The visceral sensory nucleus receiving primary afferents from VII, IX and X - has two divisions - a rostral division for taste and a caudal division for heart, abdominal viscera, baroreceptors and chemoreceptors - extends from the pons to the level of the nucleus gracilis
Which cranial nerves have somatic sensory nuclei?
V, VII, IX and X
Which cranial nerves have special sensory nuclei?
I, II, VIII
Which cranial nerves originate from the midbrain?
III, IV
Which cranial nerves originate from the pons?
V, VI, VII, VIII
Which cranial nerves originate from the medulla?
IX, X, XI, XII
What is the function of the olfactory nerve?
sense of smell
Where does the olfactory nerve exit the skull?
the cribiform plate
What is the function of the optic nerve?
sight
Where does the optic nerve exit the skull?
the optic canal
What is the function of the oculomotor nerve?
innervates medial rectus, superior rectus, inferior rectus and inferior oblique, innervates levator palebrae superioris, provides parasympathetic input to the iris and ciliary muscle
Where does the oculomotor nerve exit the skull?
superior orbital fissure
What is the function of the trochlear nerve?
innervate superior oblique
Where does the trochlear nerve exit the skull?
the superior orbital fissure
What is the function of the abducens nerve?
innervates lateral rectus
Where does the abducens nerve exit the skull?
the superior orbital fissure
Which cranial nerves go through the superior orbital fissure?
III, IV, VI and V1
Which cranial nerves go through the auditory canal?
VII and VIII
Which cranial nerves go through the jugular foramen?
IX, X, XI
Which nerve is responsible for the sensory input of the pupillary light reflex?
optic nerve
Which nerve is responsible for the motor output of the pupillary light reflex?
oculomotor nerve
What area of the brainstem does the pupillary light reflex test?
the midbrain
What type of nerve is the trigeminal nerve?
somatic sensory and branchial motor
What is the function of the trigeminal nerve?
sensory input from the face, motor input to the muscles of mastication and tensor tympani
What are the 3 branches of the trigeminal nerve?
opthalmic, maxillary, mandibular
What are the 4 trigeminal nuclei and what are their functions?
mesencephalic - proprioception, motor - motor output, chief sensory - touch, spinal trigeminal - pain
What is the course of the trigeminal nerve?
exits the brainstem as a sensory and motor root, the sensory root becomes the trigeminal ganglion and then divides into the 3 branches, the motor root goes just below the ganglion and then travels with the mandibular division into the jaw
Where does the opthalmic division of the trigeminal nerve exit the skull?
the superior orbital fissure
Where does the maxillary division of the trigeminal nerve exit the skull?
the foramen rotundum
Where does the mandibular division of the trigeminal nerve exit the skull?
the foramen ovale
What provides the sensory input for the corneal blink reflex?
the opthalmic division of the trigeminal nerve
What provides the motor output for the corneal blink reflex?
the facial nerve
What area of the brainstem does the corneal blink reflex test?
the pons
What type of nerve is the facial nerve?
branchial motor, visceral efferent, visceral sensory and somatic sensory
What is the function of the facial nerve?
innervates the muscles of facial expression and stapedius, provides parasympathetic input to the lacrimal gland and sublingual and submandibular salivary glands, provides taste to the anterior 2/3rds of the tongue, provides somatic sensation to a small area around the external auditory meatus
What are the 2 branches of the facial nerve?
facial nerve proper and nervus intermedius
Where does the facial nerve exit the skull?
the internal acoustic meatus
What branch of the facial nerve provides innervation to the lacrimal gland?
the greater petrosal branch
What branch of the facial nerve provides taste?
chorda tympani
What structure does the facial nerve pass through but not innervate?
the parotid gland
What are the 5 terminal branches of the facial nerve?
temporal, zygomatic, buccal, mandibular, cervical
What is the function of the vestibulocochlear nerve?
hearing and balance
Where does the vestibulocochlear nerve exit the skull?
the internal acoustic meatus
What are the nuclei of the vestibulocochlear nerve?
dorsal and ventral cochlear nuclei and 4 vestibular nuclei
What is the function of the glossopharyngeal nerve?
sensation from the posterior 1/3rd of the tongue, the pharynx, middle ear and carotid body, taste to the posterior 1/3rd of the tongue, parasympathetic innervation of the parotid gland, motor innervation of stylopharyngeus
Where does the glossopharyngeal nerve exit the skull?
the jugular foramen
What is the course of the glossopharyngeal nerve?
exits the skull, forms the superior and inferior ganglia, passes between the internal and external carotid and then follows stylopharyngeus to reach the oropharynx and tongue
What is the function of the vagus nerve?
motor innervation of the soft palate, pharynx, larynx, upper oesophagus and 1 tongue muscle, parasympathetic innervation to organs, sensory from pharynx, larynx and oesophagus, taste for the epiglottis, visceral inout from baroreceptors and chemoreceptors of the aortic arch
What is the function of the recurrent laryngeal nerve?
motor innervation of vocal cords
What provides the sensory input for the gag reflex?
the glossopharyngeal nerve
What provides the motor output for the gag reflex?
the vagus nerve
What part of the brainstem does the gag reflex test?
the medulla
What is the function of the spinal accessory nerve?
motor innervation of sternomastoid and the upper part of trapezius
Where does the spinal accessory nerve enter and exit the skull?
enters via foramen magnum and exits via jugular foramen
What is the function of the hypoglossal nerve?
motor innervation of the intrinsic and extrinsic muscles of the tongue (except palatoglossus)
Where does the hypoglossal nerve exit the skull?
hypoglossal foramen
Which way will the tongue deviate in a hypoglossal nerve lesion?
the tongue will deviate towards the side of the lesion
