Brain Stem Cranial Nerves Flashcards
What is cranial nerve 1?
olfactory nerve
What is cranial nerve 2?
optic nerve
What is cranial nerve 3?
oculomotor nerve
What is cranial nerve 4?
trochlear nerve
What is cranial nerve 5?
trigeminal nerve
What is cranial nerve 6?
abducens nerve
What is cranial nerve 7?
facial nerve
What is cranial nerve 8?
vestibulocochlear nerve
What is cranial nerve 9?
glossopharyngeal nerve
What is cranial nerve 10?
vagus nerve
What is cranial nerve 11?
accessory nerve
What is cranial nerve 12?
hypoglossal nerve
What cranial nerves are connected with the forebrain?
the olfactory (1) and optic (2) nerve
What cranial nerves arise from the brainstem?
cranial nerves 3 to 12
Where does the oculomotor nerve emerge from?
the interpeduncular fossa from the ventral surface of the midbrain
what does the trochlear nerve (4n) wind around after exiting the dorsal surface of the isthmus?
the cerebral peduncle
where does the trochlear nerve exit?
the dorsal surface of the isthmus
Where does the trigeminal nerve emerge from?
the basilar pons
what are the two parts of the trigeminal nerve?
the larger sensory root
the smaller motor root
where does the abducens nerve emerge from?
the caudal border of the pons
where do the facial nerve and vestibulocochlear nerve leave the brainstem from?
the lateral part of the trapezoid body of the hindbrain
The rootlets of the glossopharyngeal nerve (9n), vagus nerve (10n), and accessory nerve (11n) form a line where?
at the lateral margin of the caudal hindbrain
The rootlets of the hypoglossal nerve emerge from where?
the lateral border of the pyramid.
the paired oculomotor nuclei are found where?
at the level of the superior colliculus
(close to the midline, and ventral to the periaqueductal grey matter.)
The fibers of the oculomotor nerve course through ___ on their way to ___.
- the red nucleus
- the interpeduncular fossa
The main oculomotor nucleus contains somatic motor neurons that supply what?
all the eye muscles except the superior oblique and the lateral rectus muscles.
The smaller Edinger–Westphal nucleus contains preganglionic parasympathetic neurons that supply what?
the constrictor of the pupil and the ciliary muscle
What supplies the constrictor of the pupil and the ciliary body?
preganglionic parasympathetic neurons of the smaller Edinger–Westphal nucleus
Damage to the oculomotor nerve results in what?
a divergent squint
drooping of the eyelid
dilatation of the pupil.
what is divergent squint?
when the eye on the paralyzed side is pulled laterally and downwards away from the line of vision
drooping of the eyelid is called:
ptosis
How does damage to the oculomotor nerve cause ptosis?
due to partial paralysis of the eyelid raising muscle
Where is the trochlear nucleus located?
immediately caudal to the oculomotor complex dorsolateral to the medial longitudinal fasciculus
What segment of the brainstem is the trochlear nucleus in?
the isthmus
The small trochlear nerve exits where?
the dorsal surface of the brain stem
.The trochlear nerve crosses the midline in the ___ before winding around the ___.
- superior medullary velum
- cerebral peduncle
What muscle does the trochlear nerve supply?
the superior oblique muscle of the eye.
what does the trigeminal nerve supply?
the skin of the face
the muscles of mastication (the chewing muscles)
what are the chewing muscles called?
the muscles of mastication
The sensory fibers of the trigeminal nerve connect to:
a series of large nuclei extending from the rostral hindbrain to the spinal cord
The principal sensory trigeminal nucleus is found where?
at the level where the trigeminal nerve connects with the hindbrain
The trigeminal motor nucleus lies ___ to the principal sensory nucleus.
medial
What are all the nuclei of the trigeminal complex?
the (principal) sensory trigeminal nucleus
the trigeminal motor nucleus
the spinal (descending) nuclei
the mesencephalic nuclei
The spinal nucleus of the trigeminal complex is found where?
in the dorsolateral hindbrain at all levels below the principal nucleus
the spinal nucleus of the trigeminal complex is continuous caudally with what?
the substantia gelatinosa of the spinal cord.
The mesencephalic nucleus of the trigeminal system is ___ in low power sections.
small and difficult to see
What does the mesencephalic nucleus of the trigeminal system consist of?
a single layer of large round cells on the edge of the periaqueductal gray matter of the midbrain.
What does the abducens nerve supply?
the lateral rectus muscle of the eye
The abducens nucleus lies next to what?
the midline close to the medial longitudinal fasciculus.
The fibers of the emerging abducens nerve can be seen running ___ through the ___.
- dorsoventrally
- tegmentum of the hindbrain
the facial nerve supplies what?
the muscles of the face
taste sensory fibers to the front of the tongue
parasympathetic fibers to the submandibular salivary gland and other small glands in the head
The motor fibers leaving the main facial nucleus take an unusual course through the hindbrain. They travel ___ to curl around the ___ before heading ___ to exit the brainstem ventral to the ___.
- dorsomedially
- abducens nucleus
- ventrolaterally
- trigeminal sensory nucleus
Taste fibers in the facial nerve connect with what nucleus?
the nucleus of the solitary tract.
The vestibulocochlear nerve receives sensory fibers from:
the organs of balance (mainly the semicircular canals) and hearing (the cochlea).
In a transverse section of the junction of the pons and medulla, the vestibulocochlear nerve enters the brainstem as___, which straddle the___.
- two separate bundles
- inferior cerebellar peduncle
Those vestibulocochlear nerves entering ventral to the inferior cerebellar peduncle are the ___,
vestibular fibers
Those vestibulocochlear nerves seen dorsal and lateral to the inferior cerebellar peduncle are the ___.
cochlear fibers
The dorsal and ventral cochlear nuclei are seen as:embedded within the fibers of the cochlear nerve as is arches around the peduncle.
pale areas
The dorsal and ventral cochlear nuclei are embedded within the ___ as is arches around the ___.
- fibers of the cochlear nerve
- inferior cerebellar peduncle
What is the most prominent vestibulocochlear nucleus?
the dorsal cochlear nucleus
When is the dorsal cochlear nucleus easily recognizable in sections?
as it surmounts the inferior cerebellar peduncle
What four nuclei comprise the vestibular nuclear complex?
superior, lateral, medial, and spinal (descending) vestibular nuclei
The four nuclei of the vestibular nuclear complex are arranged within a ___-shaped area in the ___.
- diamond
- floor of the fourth ventricle
The glossopharyngeal nerve receives what? , which terminates in the nucleus of the solitary tract.
taste fibers from the posterior third of the tongue
where does the glossopharyngeal nerve that receives taste fibers terminate?
the nucleus of the solitary tract
The glossopharyngeal nerve contains parasympathetic fibers that supply what?
the parotid salivary gland
The glossopharyngeal nerve contains parasympathetic fibers that supply the parotid salivary gland which arises where?
in the inferior salivatory nucleus.
The glossopharyngeal nerve supplies:
single pharyngeal muscle
the palatoglossus
the parotid salivary gland
The glossopharyngeal nerve supplies a single pharyngeal muscle, the palatoglossus, with fibers that arise in what?
the nucleus ambiguous.
The vagus nerve supplies parasympathetic fibers to what?
the thoracic and abdominal viscera.
The parasympathetic nucleus of the vagus (the dorsal motor nucleus of the vagus) lies just medial to what? in sections of the open medulla.
the sulcus limitans
The parasympathetic nucleus of the vagus is the:
the dorsal motor nucleus of the vagus
The nucleus of the solitary tract lies ___ to the dorsal motor nucleus of the vagus.
just lateral
The nucleus of the solitary tract receives taste fibers from where?
the facial, glossopharyngeal and vagus nerves
general visceral afferent fibers from the vagus nerve
The nucleus ambiguous contains what type of neurons?, which supply the pharynx, palate, and larynx muscles via the vagus, cranial accessory, and glossopharyngeal nerves.
large multipolar motor neurons
The nucleus ambiguous contains large multipolar motor neurons, which supply what via the vagus, cranial accessory, and glossopharyngeal nerves?
the pharynx, palate, and larynx muscles
The nucleus ambiguous contains large multipolar motor neurons, which supply the pharynx, palate, and larynx muscles via what?
the vagus, cranial accessory, and glossopharyngeal nerves.
The cranial part of the accessory nerve arises from where?
the nucleus ambiguous
The cranial part of the accessory nerve is considered by many to be part of:
the vagus nerve
What does the cranial part of the accessory nerve contribute to?
the vagal supply of the pharynx.
The spinal root of the accessory nerve supplies what?
sternomastoid and trapezius muscles in the neck
The spinal root of the accessory nerve is what type of nerve?
a motor nerve
The spinal root of the accessory nerve arises from where?
motoneurons in cervical spinal cord levels C2 to C4.
The spinal root of the accessory nerve travels into the ___ to join briefly with the ___ before descending into the ___.
- cranial cavity
- vagus nerve
- posterior triangle of the neck
The hypoglossal nerve supplies what?
the muscles of the tongue
The hypoglossal nucleus lies ___ to the medial longitudinal fasciculus
immediately dorsal
The hypoglossal nucleus lies medial to the ___.
dorsal motor nucleus of the vagus in the floor of the fourth ventricle
The hypoglossal nerve fibers travel ___ to emerge between ___ .
- ventrally
- the inferior olive and pyramid
The fibers that travel in the cranial nerves can be classified on the basis of ___.
- their functions
Efferent (motor) fibers are classified as either”:
somatic efferent,
visceral efferent
branchial efferent
Afferent (sensory) fibers are classified as either:
somatic sensory,
visceral sensory,
special sensory
What is/are the functional component/s of the Olfactory nerve?
special sensory
What is/are the functional component/s of the optic nerve?
special sensory
What is/are the functional component/s of the oculomotor nerve?
somatic motor
visceral motor
What is/are the functional component/s of the trochlear nerve?
somatic motor
What is/are the functional component/s of the trigeminal nerve?
somatic motor
branchial motor
What is/are the functional component/s of the abducens nerve?
somatic motor
What is/are the functional component/s of the facial nerve?
somatic sensory
branchial motor
What is/are the functional component/s of the vestibulocochlear nerve?
special sensory
What is/are the functional component/s of the glossopharyngeal nerve?
branchial motor
visceral motor
special sensory
visceral sensory
What is/are the functional component/s of the vagus nerve?
visceral motor
visceral sensory
branchial motor
What is/are the functional component/s of the accessory nerve (spinal part)?
somatic motor
What is/are the functional component/s of the hypoglossal nerve?
somatic motor
What is the function of the special sensory component of the olfactory nerve?
sensation of smell
What is the function of the special sensory component of the optic nerve?
sensation of vision
What is the function of the somatic motor component of the opculomotor nerve?
controls four of the six eye muscles and the eyelid msucles
What is the function of the visceral motor component of the oculomotor nerve?
parasympathetic control of the lens and pupil
What is the function of the somatic motor component of the trochlear nerve?
controls the superior oblique muscle of the eye
What is the function of the somatic sensory component of the trigeminal nerve?
sensation from the skin of the face
What is the function of the branchial motor component of the trigeminal nerve?
controls the muscles of the jaw
What is the function of the somatic motor component of the abducens nerve?
controls the lateral rectus muscle of the eye
What is the function of the somatic sensory component of the facial nerve?
taste sensation from the front of the tongue
What is the function of the branchial motor component of the facial nerve?
controls the muscles of the face
What is the function of the special sensory component of the vestibulocochlear nerve?
sensations of hearing and balance
What is the function of the branchial motor component of the glossopharyngeal nerve?
controls one of the muscles of the pharynx
What is the function of the visceral motor component of the glossopharyngeal nerve?
parasympathetic control of the parotid salivary gland
What is the function of the special sensory component of the glossopharyngeal nerve?
taste sensation from the back part of the tongue
What is the function of the visceral sensory component of the glossopharyngeal nerve?
detection of blood pressure changes
What is the function of the visceral motor component of the vagus nerve?
parasympathetic control of internal organs of the thorax and abdomen
What is the function of the visceral sensory component of the vagus nerve?
sensation from the internal organs
What is the function of the branchial motor component of the vagus nerve?
controls the muscles of the pharynx and larynx
What is the function of the somatic motor component of the accessory nerve (spinal part)?
controls two large neck muscles
What is the function of the somatic motor component of the hypoglossal nerve?
controls the muscles of the tongue