Branchiomeric Cranial Nerves (Quiz 2) Flashcards
What is the largest CN?
trigeminal n.
What are the 2 axonal categories for the trigeminal n.?
somatic sensory and pharyngeal motor
it is primarily responsible for transmitting tactile, proprioceptive, temp., and pain from the head
The input from CN V projects to the _______________, cerebellum, and reticular formation
cerebral cortex
What are the 3 divisions for the trigeminal n.?
-ophthalmic (V1) sensory
-maxillary (V2) sensory
-mandibular (V3) sensory and motor
The 3 divisions of the trigeminal nerve converge in a large ganglion in the mid pons. What is this ganglion called?
trigeminal ganglion/semilunar/ Gasserian ganglion
The 3 sensory nuclei of the trigmeinal nerve receive afferents from a long continuous column from the rostral midbrain to the upper spinal cord. What are they 3 nuclei called?
1) sensory nucleus (also called main sensory nucleus bc its the main nucleus)
2) spinal nucleus (just caudal to the sensory nucleus)
3) mesencephalic nucleus (rostral to midbrain)
Each component of CN V is responsible for sensory info from a different region of the face. The ophthalmic branch or CN V1 receives input from the….
-upper eyelids
-supraorbital area
-over frontal b.
-dura mater of anterior cranial fossa
-frontal sinus
-nasal cavity
What are the main nerves from CN V1?
-nasociliary n.
-frontal n.
-lacrimal n.
What does CN V2 innervate?
-maxila
-middle face
-upper teeth
-hard palate
What are the main nerve branches for CN V2?
boards q
-middle meningeal n.
-zygomatic n.
-pterygopalatine n.
palatine n.
-superior alveolar n.
-infraorbital n.
What is the largest division of the trigeminal n.?
CN V3 (mandibular division)
Which division of the trigeminal nerve is both sensory and motor?
CN V3 (mandibular division)
What does CN V3 innervate?
-lower jaw
-bottom teeth
-oral cavity
-gingiva
The motor component of CN V3 is a single, slender nerve with 1 nucleus. What is the nucleus called?
trigeminal motor nucleus
The motor component of CN V3 leaves the motor nucleus at superior pontine sulcus, innervates muscle of 1st pharyngeal arch. What muscles are here?
-muscles of mastication (pterygoid, masseter, and temporalis)
-mylohyoid
-anterior digastric
-tensor tympani
T/F: the trigeminal nerve has 4 nuclei- 3 sensory and 1 motor
true
Which trigeminal nucleus processes proprioception from the jaw and has mechanoreceptors from teeth?
mesencephalic nucleus
Unconscious control of biting, chewing, and swallowing due to sensory feedback from _____________ nucleus of the trigeminal n.
mesencephalic
What is the jaw jerk reflex/ biting reflex?
Which nucleus of the trigeminal n. has tactile and proprioceptive sensation and 2 ascending pathways:
1) anterior trigeminothalamic tract (fibers cross and synapse in VPM)
2) posterior trigeminothalamic tract (uncrossed fibers to VPM (oral cavity))?
principle nucleus/ main nucleus/ sensory nucleus of trigeminal
What is the only shared nucleus for CNs 5, 7, 9 and 10?
spinal trigeminal nucleus
The spinal trigeminal nucleus is a long nucleus. What does the caudal portion process?
pain and temp (free nerve endings bring in this info with C fibers and A delta fibers, A delta is faster than C fibers)
The 2nd order neurons from the caudal portion of the spinal trigeminal nucleus form a crossed pain pathway posterior ______________________
trigeminothalamic tract (homologous to lamina 2 substantia gelatinosa and spinothalamic tract)
Which trigeminal nucleus innervates the muscles of mastication?
trigeminal motor nucleus
Which trigeminal nuclei innervate the face?
spinal trigeminal nucleus and main trigeminal sensory nucleus
Which trigeminal nucleus innervates the jaw muscles and joints?
mesencephalic trigeminal nucleus
The facial, glossopharyngeal, and vagus nerves all contain the same 4 axonal categories. What are they?
1) somatic sensory (tactile, touch, pain)
2) visceral sensory (chemoreceptors, baroreceptors)
3) visceral motor (ANS)
4) pharyngeal motor (going to muscles)
All somatic sensory axons from CN VII, IX, and X enter the _______________ tract and then __________________ nucleus
trigeminal, spinal trigeminal
All visceral sensory axons from CN VII, IX, and X enter the ___________ tract and then ___________ nucleus
solitary, solitary
(this is the major visceral sensory nucleus of the brainstem)
Originating in the pons, most of the facial fibers are pharyngeal __________ innervating muscles of facial expression and _______________
motor, stapedius
What is the origin nucleus of all facial muscles?
facial motor nucleus
The facial n exits the skull via the ________________ foramen
stylomastoid
The facial nerve enters which gland but does not innervate it?
parotid gland
What are the 5 terminal branches of the facial nerve?
-temporal n.
-zygomatic n.
-buccal n.
-mandibular n.
-cervical n.
What are the muscle groups that the facial nerve innervates?
-orbital group
-nasal group
-oral group
-auricular
-occipitofrontalis
The facial motor nucleus is controlled by what tract?
corticobulbar tract
Corticobulbar fibers originate in the head and face portions of the _________________. They project bilaterally- our muscles are used simultaneously
precentral gyrus
T/F: LMNs from the motor facial nerve are ipsilateral, most efferents below the eye are crossed
true
The limbic system (emotions) projects to which nucleus?
facial motor nucleus
What are the 4 categories of axons for the facial n.?
1) somatic sensory (spinal trigeminal nucleus)
2) visceral sensory (solitary nucleus)
3) motor pharyngeal (biggest category, goes out to all the muscles besides eyes and tongue)
4) visceral motor (ANS)
General sensory fibers (somatic sensory) in the facial n. are responsible for transmitting signals to the brain from the _________________________, as well as the skin over the mastoid process and lateral pinna
external acoustic meatus
Special sensory taste info from the anterior 2/3 of tongue gets input sent to the solitary nucleus from CN _____
VII
What is the order of the facial nerve corneal blink reflex?
test q
-corneal blink reflex involves CN V and VII
-stimulus= cotton swab on the cornea
-receptor is in the cornea
-sensory innervation by CN v1 (ophthalmic branch)
-axons synapse enter spinal trigeminal tract
-synapse in spinal trigeminal nucleus
-interneurons project to facial motor nucleus bilaterally via reticular formation
-efferent output from facial motor nucleus closes the eyes (response)
The glossopharyngeal n. is a mixed nerve that consists of both the motor and sensory fibers. What are the 4 categories of axons + 4 corresponding nuclei located in the medulla?
1) pharyngeal motor, info goes out from the ambiguous nucleus
2) visceral motor, info goes out of the inferior salivary nucleus to the ANS
3) somatic sensory, info goes into the spinal nucleus of the trigeminal n.
4) visceral sensory, info comes from chemoreceptors and goes into the solitary nucleus
Which nerve has this somatic sensory function?
-info goes out to the spinal nucleus of the trigeminal n.
-sensory input from the posterior 1/3 of the tongue, palatine tonsils, oropharynx, mucosa of the middle ear, pharyngotympanic tube and the mastoid air cells
glossopharyngeal n.
Which nerve has this visceral/special sensory function?
-sensory info from the carotid body to the solitary nucleus
-sense of taste fro, the posterior 1/3 of tongue to solitary nucleus
glossopharyngeal n.
Which nerve has a parasympathetic function where the inferior salivary nucleus has axons innervating the salivary parotid gland?
glossopharyngeal n.
Which nerve has a pharyngeal motor function where the info originates in the ambiguous nucleus and axons innervate the muscles derived from the 3rd pharyngeal arch- stylopharyngess muscle and the superior pharyngeal constrictor muscle (these constrict to allow swallowing)?
glossopharyngeal n.
Which CNs use the ambiguous nucleus?
CN 9, 10, and 11
The nucleus ambiguous is located in the anterolateral medullary tegmentum posterior to the inferior olivary nucleus. The source of pharyngeal motor fibers are from what 2 muscles?
stylopharyngess (elevates) and superior pharyngeal constrictor muscle
Which CNs use the solitary nucleus?
CN 7, 9 and 10
The solitary nucleus is a sensory nucleus which receives the fibers from the glossopharyngeal n., but also from the facial and vagus nerves. The caudal portion of the solitary nucleus receives sensory info from the baroreceptors of the ________________, the rostral portion receives gustatory (taste) fibers from the posterior 1/3 of the tongue. This is referred to as the…..
carotid sinus, gustatory nucleus
Which 2 nuclei regulate saliva production?
solitary nucleus and the sensory nuclei of the trigeminal n.
Input from the tongue and pharynx goes to which 3 cranial nerves?
CN 7, 9 or 10
What are the 4 axonal categories with their corresponding nucleus for the vagus nerve?
test q
1) somatic sensory, spinal trigeminal nucleus
2) visceral sensory, solitary nucleus
3) visceral motor, DMX
4) pharyngeal motor, ambiguous nucleus
Which CN is this?
-somatic sensory, spinal trigeminal nucleus
>touch, pain, temp, pressure, vibration, and proprioceptive sensation from the posterior ear, external auditory meatus, and tympanic membrane
-visceral sensory, solitary nucleus
>thorax, abdominal viscera including pressure and chemoreceptors
>taste from epiglottis and soft palate
-visceral motor, ANS, DMX
>innervates the viscera, including all smooth muscles and glands
-pharyngeal motor, ambiguous nucleus
>innervates pharynx and larynx, such as the muscles of mastication
>mediate swallowing and phonation
CN X
There are 2 ganglia on the vagus nerve (superior and inferior) as it exits the ______________ foramen
jugular
Which nerve joins the vagus nerve just distal to the inferior ganglion?
spinal accessory nerve
What is the major/principle parasympathetic nucleus in the brain?
DMX
What is the order of the CN X gag reflex?
-pharyngeal reflex to monitor CN IX and X
-stimulus= touching the side of the oropharynx or roof of the mouth (tactile receptor) and sends afferent input via CN IX
-synapse in spinal trigeminal nucleus and solitary nucleus and or the nucleus ambiguous
-efferent fibers leave via CN X causing muscles to contract )response)
