Transcript Cranial Nerves 101

Cranial Nerves 101
The Nerves are Fun
On Old Olympus’ Towering Tops
...
• Say the names of the cranial nerves backwards
in less than 60 seconds.
• No,no,no. Not yrotcaflo, citpo, rotomoluco ...
• Say them starting with the hypoglossal?
Describe the
brainstem exit,
cranial exit and
general functions
of cranial nerves
1 - 6.
Where are the olfactory
receptors? What is the difference,
if any between the olfactory nerve
and the olfactory tract?
Olfactory Nerve (SVA), Bulb and
Tract
• Olfactory Epithelium
• Nerve and Cribiform
Plate
• Olfactory Bulb
• Olfactory Tract to
Piriform Cortex and
Amygdala
Optic System 101
• Retina
• Optic Nerve (SSA),
Chiasm, Tract
• Thalamus (Lateral
Geniculate Nucleus) and
Visual Cortex
• Superior Colliculus
3,4 and 6
• Oculomotor (GSE and GVE)
– The Main Mover
– Parasympathetic Too
• Trochlear (GSE)
– In and Down (If in, then down)
– Two odd things
– Trochlea of the Skull
• Abducens (GSE)
– All in a name
Eyeball Kinesiology
• Adduction -- Abduction
• Elevation -- Depression
• Torsion, Rotation(Medial and
Lateral)
Torsional Movements
LR6SO4
• Lateral Rectus 6
– Abducts
• Superior Oblique 4
– Depresses and adducts
• All Others 3
– Superior and Inferior
Rectus and Inferior
Oblique
– “All” except abduction
Oculomotor Parasympathetic
• Parasympathetic
– Pre- and Postganglionic
Fibers
– Ciliary Ganglia (Motor)
• Pupillary Reflex
– 2+3=Constriction
– Consensual Response
• Accomodation Reflex
Describe the
brainstem exit,
cranial exit and
general functions
of cranial nerves
7-12.
In addition to moving the face,
what else does the facial nerve
do? Where would a lesion have
to be to involve all of the
functions of the facial nerve?
The Full Facial
• SVE
– Muscles of Facial Expression
• SVA
– Taste Anterior 2/3 Tongue
– Geniculate Ganglia (Sensory)
and Solitary Nucleus
• GVE=Parasympathetic
– Superior Salivatory Nuc
– Sphenopalatine Ganglia
• Lacrimal Gland
– Submandibular Ganglia
• Lingual and Submandibular
Glands
• GSA?
Describe the Anatomy of the
Motor Part of the Facial Nerve.
Describe the effects of an LMN
lesion and an UMN lesion that
affects this nerve.
Upper and Lower Face Muscles
• LMN Damage
– Upper and Lower
Ipsilateral Face
Paralysis
• UMN Damage
– Only Lower
Contralateral Face
Paralysis
The Labyrinth - Vestibule,
Semicircular Canals, and Cochlea
Semicircular Canals
Vestibule
Cochlea
Primary Afferent Fibers
• Hair Cell Receptors
• Cochlear Duct
– Spiral Ganglia
– Cochlear Nuclei
– Damage = Ipsilateral Deafness
Hair
Cells
Ganglia
• Ampulla and Utricle (and Saccule)
– Scarpa’s Ganglia
– Vestibular Nuclei
– Damage = Ipsilateral Imbalance
Nucleus
Vagus Nerve
• Exit
– Post Olivary Sulcus
– Jugular Foramen
• Functional Components
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–
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Speech and Swallowing
Lower Motor Neuron _____________
Thorax and Abdomen
Parasympathetic _____________
ANS Reflexes and Larynx Sensation
Visceral Sensory _____________
Uvula and Epiglottis
Taste _____________
External Auditory Meatus
Touch and Pain _____________
Glossopharyngeal Nerve
• Exit
– Post Olivary Sulcus
– Jugular Foramen
• Functional Components
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–
–
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–
Lower Motor Neuron _____________
Parasympathetic _____________
Salivation - Parotid Gland
ANS Reflexes and Pharynx Sensation
Visceral Sensory _____________
Taste _____________
Posterior 1/3 Tongue
Touch and Pain _____________
External Ear
“Swallowing”
The Gag Reflex
?
• Sensory Part
– Glossopharyngeal
• Motor Part
– Vagus
• And Uvula Deviation
cn10
cn9
Explain the different effects of
UMN and LMN lesions of the
hypoglossal nerve on tongue
protrusion.
Damage to Cranial Nerve 12
• Damage to the Lower Motor Neuron
– Damage to Nerve or Nucleus
– Tongue Deviate Toward the Lesion
• Damage to the Upper Motor Neurons
– Damage to Corticobulbar Fibers
– Tongue Deviates Away from the Lesion
Hypoglossal Lower Motor
Neuron Damage
• Tongue Deviates
Toward the Lesion
– Damage to the Nucleus
– Damage to the Nerve
– Deviates to the Weak
Side
Hypoglossal Upper Motor
Neuron Damage
• Tongue Deviates Away from the Lesion
• Damage to Axons from the Cerebral Cortex
– Motor Cortex (Lateral)
– Internal Capsule
– Corticobulbar Fibers
• Contralateral Termination
Upper Motor Neuron
Lesion
• The Contralateral Tongue
cannot Push!
• Deviates to the Weak
Side
The Grand Finale
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The Case
Faculty Evaluation
Golden Neuron Quiz
Your Questions Please
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