Spinal nerves Flashcards
Which CN have Parasympathetic nuclei
III, VII, IX, X
What are the four Parasympathetic Ganglia
Ciliary, Otic, Pterygopalatine, Submandibular
What pathways do Preganglionic Parasympathetic nerves travel on ?
CN III, VII, IX
What pathway do Postganglionic Parasympethietic fibers travel on?
CN V
Where do Preganglionic Sympathetic fibers originate
T1-T4
Where do Preganglionic Sympathetic fibers usually terminate?
Superior Cervical Ganglion
How do Postganglionic Sympathetic fibers reach their target?
1- Traveling with Internal Carotid Artery then on to External Carotid Artery 2- Following Internal Carotid Artery then riding the Trigeminal System 3- Traveling on their own
Where do the Olfactory Nerve Originate?
Bipolar neuronal bodies in the Olfactory Epithelium
What cavity to the Olfactory nerves pass through
Cribiform Plate of the Ethmoid Bone
Where do the Olfactory Axions Terminate?
Olfactory Bulb
What is Anosmia
Loss of Smell
What is Rhinorrhea
When CSF drips from the nose
What is the pathway for the Optic Nerve
Retina Posterior aspect of eyeball Optic Canal Optic Chiasm Optic Tract Thalamus Primary Visual Cortex (occipital Lobe)
Where are the cell bodies of the Optic nerve (CN II)
Ganglion cells of the Retina
What does the Vestibulocochlear nerve (CN VIII) do?
Sensory for hearing and balance
Where does the CN VIII exit the skull?
Internal Acoustic meatus
What two parts does CN VIII dived into?
Vestibular N (balance) Cochlear N (Hearing)
Where are the vestibular cell bodies located?
Lateral aspect of the Open Medulla and the Pons Vestibular Ganglion
Where are the Cochlear cell bodies located
Cochlear (spiral) Ganglion)
Where does the Vestibular ganglion send it s centeral process into
Vestibular Nuclei
Where does the peripheral process of the Vestibular Ganglion project into?
Vestibular apparatus
What consists of the vestibular apparatus
utricle saccule semicircular canals
Where does the Cochlear Ganglion send its centeral process into?
Cochlear Nuclei
Where does the Cochlear Ganglion send its Peripheral process into?
Cochlea
What are the purely sensory Nerves
CN I, II, VIII
What are the Purely Motor Nerves
III, IV, VI
What fiber types does the Oculomotor nerve (CN III) have?
Somatic Motor Parasympathetic
What does the Oculomotor Nerve do?
Somatic motor to all extraocular mm except - lateral rectus superior oblique
What are the two divisions of CN III
Superior division Inferior Division
What muscles does the superior division of CN III innervate?
Superior Rectus Levator Palpebrae
What muscles does the inferior division of CN III innervate?
Medial rectus inferior rectus inferior oblique
Where are the Preganglionic Parasympathtic cell bodies of CN III located?
Edinger Westfall nucleus In the Pons
How do the fibers of the Preganglionic Parasympathetic of CN III travel?
Along the inferior division of III
Where do the Preganglionic Parasympathetic CN III synapse
Ciliary Ganglion
How do the Postganglionic Parasympathetic fibers travel?
direct to eye along Short Ciliary N
What do the Parasympathetic of CN III do?
innervate the Sphincter pupillae
Ciliaris
What happens when the Parasympathetic of CN III are lesioned?
Supplies the sphincter pupillae and the ciliary muscles of the eye - pupil is directed down and out. Droopy upper eyelid
What does the Trochlear Nerve Innervate?
Superior Oblique M
What is unique about the path of CN IV
It travels posteriorly then anteriorly to target.
Where does CN IV enter?
Superior Orbial Fissue
Where do the cell bodies of CN IV originate?
Trochlear Nucleus of the midbrain
What happens when CN IV is lesioned?
Patient is unable to look down when eye is adducted.
What does the Adbucens Nerve CN (VI) innervate?
Lateral Rectus M
Where do the cell bodies of the Abducens Nerve Originate?
Abducens Nucleus - mid pons
Where do the Adbucens axions originate and exit from the brainstem?
Pons Exit through the Pontomedullary Junction
How does CN VI exit the skull?
They pass through the cavernous Sinus and enter the eye through the Superior Orbital Fissure
What happens if CN VI is lesioned
pt is unable to abduct the eye
What does the Spinal Accessory Nerve (XI) do?
Innervates Trapezius Sternocleidomastoid
Where does the CN XI nerve originate?
Spinal Rootlets of Spinal accessory Nucleus of upper 5 segments of spinal cord
What happens if XI is lesioned
Pt experiences shoulder droop
What things pass through the jugular foramen
CN IX, X, XI, Jugular Vein The hypoglossal nerve crosses the jugular vein.
What does the Hypoglossal Nerve ( CN XII) do
Somatic Motor to the Tongue
Where do the cell bodies of CN XII originate?
Ventromedial position of the Central Gray matter of the Medulla Hypoglossal Nucleus
in the Medulla
How does CN XII leave the cranial cavity
Hypoglossal canal
CN XII has a relation to what?
Occipital Artery
What happens when CN XII is lesioned?
Protruded tongue deviates to affected side.
What are the purely motor CN?
III, IV, VI, - all for the eyes
What are the three divisions of the Trigeminal CN V nerve
Ophthalmic V1 Maxillary V2 Mandibular V3
What is the CN V?
Principle sensory nerve of the head and small motor component.
Where are the cell bodies of CN V
Trigeminal Ganglion - Sensory Trigeminal Motor Nucleus - located in the Pons
Where does the Ophthalmic Division of CN V pass through?
Superior Orbital Fissure - enters orbit.
What does the Ophthalmic Division of CN V divide into?
Frontal Nerve Lactimal Nerve Nasociliary Nerve
Where does the Maxillary Division pass through
Foramen Rotundum
What does the Maxillary Division divide into?
- infraorbital nerve
- greater and lesser palatine nerves
- zygomatic nerves
- posterior superior alveolar nerves
- nasal branches supplying superior and middle concha and nasal septum
Where does the Mandibular Division pass through?
Foramen ovale - enters infratemporal fossa
What does the Mandibular Division divide into
inferior alveolar nerve lingual nerve buccal nerve auriculotemporal N Motor Nerves of Mastication
What does the Facial Nerve do (CN VII)
Somatic Motor Preganglionic Parasympathetic Fibers Somatic Sensory Taste Fibers
Where does the CN VII exit?
Internal Acoustic Meatus
Where do the cell bodies of the Preganglionic Parasympathetic Cell bodies of CN VII arise?
Superior Salivary Nucleus- Rostral end of Medulla
Where does the cell bodies of the Somatic Motor fibers of CN VII arise?
Facial Motor Nucleus - Top of Medulla Bottom of Pons
Where are the taste afferent cell bodies for the anterior 2/3 of the tounge.
Geniculate Ganglion- located in the bend of the Facial Canal in temporal Bone.
Where is the Geniculate Ganglion located?
Bend of Facial Canal in the Temporal Bone
The taste fibers of CN VII innervate what?
anterior 2/3 of tongue
The Somatic Sensory of CN VII innervates what?
External Ear
Where do the somatic motor and sensory fibers of CN VII exit?
Stylomastoid foramen
What nerves does CN VII give off in the temporal bone?
Greater Petrosal nerve (preganglionic Parasympathetic) Chorda Tympani (Preganglionic Parasympathetic and Taste)
Where does the Greater Petrosal Nerve Synapse?
Pterygopalatine Ganglion
Where does the Chorda Tympani Synapse of the Intermediate Nerve ( CN VII)
Submandibular Ganglion
What does the Pterygopalatine Ganglion innervate?
Lacrimal Gland
Nasal Mucosa,
Palatal mucosa
What does the Submandibular ganglion innervate?
Submandibular salivary gland Sublingual Salivary Gland
What does the Glossopharyngeal nerve (CN IX) do? Fiber Types?
Somatic Motor
Preganglionic Parasympathetic
Somatic Sensory
Visceral Sensory
IX Preganlionic parasympathetic fibers originate where?
Inferior salivary nucleus - Medulla
IX Preganlionic parasympathetic fibers pass via what? to Where?
Lesser Petrosal N
Otic Ganglion
to the paroitid gland
IX Postganglionic Parasympathetic fibers go to where?
Parotid gland - stimulate secretion
IX Somatic Sensory fibers do what?
Carry pain, temp, touch From posterior 1/3 of tongue Tonsils, Soft Palate Sides of Pharynx
IX Somatic Sensory cell bodies are located?
Inferior Ganglion of IX
IX Visceral Sensory innervate what? Cell bodies are located where?
- Carotid sinus
- Carotid Body
- Inferior Ganglion
IX Taste Fibers have cell bodies in ?
Inferior Ganglion of IX
What happens when the Somatic Fibers of CN III are lesioned
Eye looks down and out
CN IV Trochlear nerve does what to the eye
Depresses Abduct Internally rotates eye
CN VI does what?
ABducts the eye - moves eye away from midline
What 2x nerves innervate swallowing?
IX, X
If there is damage to the vagus nerve which happens to the Uvula?
It deviates away from the side of the lesion.
What nerve emerges from the pre-olivary sulcus?
CN XII (hypoglossal)
What nerve(s) emerge from the post-olivary sulcus?
CN IX (glossopharyngeal nerve) CN X (Vagus), CN XI (accessory nerve)
Where does the nucleus for the vagus nerve (CN X) originate?
Medial aspect of the Central Grey Matter of the Medulla Called the Dorsal Nucleus of Vagus
What does the Nucleus of Solitary Tract do?
Taste and other visceral sensory information.
What three nuclei are in the Central Grey Matter of the Medulla
CN X (Dorsal Nucleus of Vagus) CN XII (Hypoglossal Nucleus) Nucleus Solitarius
Where is the Nucleus Ambiguous.
In the Open Medulla.
What does the Nucleus Ambiguous do? What CN contribute to this? Fiber Types
Swallowing, Vocalization CN IX, X Somatic Motor (Efferent)
What regulates the IML?
The Descending hypothalamo-spinal sympathetic tract
Medial Medullary Syndrome affects what? What Artery?
Anterior Spinal Artery
- Pyramids - Contralateral spastic Hemiparesis
- Medial Lamniscus - Contralateral Vibratory and tactile sense
- Hypoglossal Nucleus - Ipsilateral flaccid hemiparesis (Tongue points to side of lesion)
What two nerves exit the Internal Acoustic Meatus?
VIII (VestibuloChoclear) and VII Facial Nerve.
What is affected in Lateral medullary Syndrome of Wallenburg
- Spinal Tract
- Trigeminal Nerve - Ipsilateral Face Numbness
- Inferior Cerebellar Penuckle- Ipsalateral Ataxia
- Lateral Spinothalamic Tract- Contralateral Hemibody numbness
- Vestibular Nuclei - Vertigo
- Nucleus Ambiguus - dysphagia, dysarthria
- Descending Sympathetic Tract- Horner Syndrome
What Nerves emerge from the Pontomedulary Junction?
CN VI, VII, VIII
What nerve emerges from the Pons
CN V (Trigeminal Nerve)
What Nuclei are contained in the Tegmentum of lower Pons
- abducens nucleus (VI)
- facial nerve nucleus (VII)
- vestibulocochlear nuclei (vestibular nuclei and cochlear nuclei) (VIII)
What forms the Facial Colliculus?
The Facial axions looping around the Abducens Nucleus
What Nerves are in the Tegmentum of the Mid-Pons
- the ‘chief’ or ‘pontine’ nucleus of the trigeminal nerve sensory nucleus (V)
- the motor nucleus for the trigeminal nerve (V)
Millard-Gubler syndrome
Symptoms result from the functional loss of several anatomical structures of the pons, including the sixth (VI) and seventh (VII) cranial nerves and fibers of the corticospinal tract.
- Ipsilateral facial paralysis (due to interruption of the facial nerve)
- Ipsilateral lateral rectus palsy (due to interruption of the abducens nerve)
- Contralateral hemiplegia (due to interruption of the corticospinal tract)
Millard-Gubler syndrome is a lesion where? What Artery?
Lesion in the ventral pons
Artery: anterior inferior cerebellar artery
What is the Tentorial Notch?
Where the tentorum ceribeli dural folds meet. Can be a place of swelling and can compress the Midbrain and the CN III, IV.
Where does CN III emerge
In the interpeduncular fossa
Where does CN IV exit the brainstem?
Dorsal side of Midbrain
What do the superior Coliculi do
Visual reflexes
What do the inferior Coliculi do?
Auditory reflexes. Determine location of sound.
What Nuclei are in the Midbrain
- CN III - oculomotor- Motor and
- edinger westfall (parasympathetic)
- CN IV - Trochlear - *loops around to the contralateral side*
What are the inferior and superior of colliculi known as?
corpora quadrigemina
Contribute to the TectoSpinal Tract - Blinking and head turning reflexes.
What does the Periaqueductal Gray Matter do?
Secretes pain limiting endorphines.
Ventral midbrain syndrome- Weber’s
Affects corticospinal tract and fibers of oculomotor nerve Contralateral hemiparesis Ipsilateral CN III palsy
