week 7 - neuro (cranial nerves and CN nuclei) Flashcards
What goes through the superior orbital fissure (lateral to medial)?
Superior ophthalmic vein, lacrimal nerve, frontal nerve, trochlear nerve, abducent nerve, oculomotor nerve, nasociliary nerve
What goes through the cribriform plate?
Olfactory nerve, anterior and posterior ethmoidal artery
What goes through the optic canal?
Optic nerve and ophthalmic artery
What goes through the foramen rotundum?
Maxillary division of the Trigeminal Nerve
What goes through the foramen ovale?
The mandibular division of the trigeminal nerve and the lesser petrosal nerve
What goes through the carotid canal?
Internal carotid artery and carotid sympathetic plexus
What goes through the foramen spinosum?
Middle meningeal artery , meningeal branch of mandibular nerve
What goes through the hiatus of canal for lesser petrosal nerve?
Lesser petrosal nerve and superior tympanic artery
What goes through the hiatus of canal for greater petrosal nerve?
Greater petrosal nerve
What goes through the hiatus of canal for greater petrosal nerve?
Greater petrosal nerve
What goes through the internal acoustic meatus?
Labyrinthine artery and vein, vestibulocochlear and facial nerve
What goes through the jugular foramen?
Internal jugular vein, glossopharyngeal nerve, vagus nerve, accessory nerve, inferior petrosal sinus, posterior meningeal artery
What goes through the foramen magnum?
Spinal vein, anterior spinal artery, spinal cord, spinal root of accessory nerve, vertebral artery
What goes through the condylar canal?
Condylar emissary vein
What goes through the hypoglossal canal?
Hypoglossal nerve
What goes through the mastoid foramen?
An emissary vein
What goes through the stylomastoid foramen?
Facial nerve, stylomastoid artery
What goes through the petrotympanic fissure?
Anterior tympanic artery, chorda tympani
What goes through the foramen lacerum?
Deep petrosal nerve and greater petrosal nerve
What goes through the lesser palatine foramen?
Lesser palatine nerve and artery
What goes through the greater palatine foramen?
Greater palatine nerve and artery
What goes through the incisive canal?
Nasopalatine nerve and artery
Which bones make up the cranial fossa?
Frontal, ethmoid, sphenoid, temporal, parietal, occipital
Which foramen are in the occipital bone?
Hypoglossal canal, foramen magnum
Which foramen are in the temporal bone?
Carotid canal, stylomastoid foramen, jugular foramen, mastoid foramen
Which foramen are in the sphenoid bone?
Foramen ovale, foramen spinosum, foramen rotundum?
What does the olfactory nerve do?
SVA - special sense of smell
What does the optic nerve do?
SVA - special sense of sight
What does the oculomotor nerve do?
GSE - Motor to extraocular muscles
GVE - Parasympathetic to smooth muscle in the eye
What does the trochlear nerve do?
GSE - Motor to superior oblique muscle
What does the trigeminal nerve do?
GSA- sensory to face, orbit, nose, anterior tongue
SVE - motor to muscles of mastication
What does the abducens nerve do?
GSE - motor to lateral rectus muscle
What does the facial nerve do?
GSA - sensory to skin of ear
SVA - special sense of taste to anterior tongue
GVE - motor and parasympathetic to salivary, nasal and lacrimal glands
SVE - motor to facial muscles
What does the vestibulocochlear nerve do?
SSA - special sense of hearing and balance
What does the glossopharyngeal nerve do?
GSA - sensory to posterior tongue
SVA - special sensory taste to posterior tongue
GVA - sensory from middle ear, pharynx, carotid body/sinus
GVE - motor to parotid gland (parasympathetic)
SVE - motor to stylopharyngeus
What does the vagus nerve do?
GSA - sensory to external ear
SVA - special sense of taste - epiglottis
GVA - sensory from pharynx, larynx and viscera
GVE - motor to viscera
SVE - motor to muscles of larynx/pharynx
What does the accessory nerve do?
SVE - motor to sternocleidomastoid and trapezius
What does the hypoglossal nerve do?
GSE - motor to muscles of the tongue
Which cranial nerve(s) provide motor supply to the tongue?
Hypoglossal - all muscles except palatoglossus
Vagus - palatoglossus
Which cranial nerves provide general sensation to the tongue?
Glossopharyngeal - posterior 1/3
Mandibular branch of the trigeminal nerve - anterior 2/3rds
Which cranial nerves provide taste sensation to the tongue?
Glossopharyngeal - posterior 1/3rd
Facial nerve (chorda tympani branch) - anterior 2/3rds
Which cranial nerves have parasympathetic fibres?
10, 9, 7, 3
What does the vagus nerve parasympathetics do?
Supply to the viscera of the foregut, midgut, cardiac and pulmonary plexuses
What does the glossopharyngeal parasympathetics do?
parotid salivary gland
What does the facial parasympathetics do?
tear, nasal and salivary glands
What does the oculomotor parasympathetics do?
Narrows pupils and focuses lens
What visual changes might one see in a patient with a pituitary tumour?
Bitemporal hemianopia
What is cavernous sinus syndrome?
Any pathology in the cavernous sinus that presents as unilateral ophthalmoplegia (CNIII, IV, VI dysfunction), autonomic dysfunction (horner’s syndrome) or V1 loss
What is the presentation of abducens nerve palsy?
When looking outwards, the affected eye does not abduct
What is horner’s syndrome?
Dysfunction of the parasympathetics of oculomotor (ptosis, miosis (constricted pupil) and anhydrosis
what is the clinical presentation of an oculomotor nerve lesion?
Drooping eyelid, diplopia, pupil dilation, impaired downward and inward movement of the eyeball
What is the clinical presentation of a trochlear nerve lesion?
Double vision on looking down or reading/walking down stairs
What is the presentation of a middle cranial fossa fracture?
CFS otorrhoea and rhinorrhoea, haematotympanum, conductive or sensorineural hearing loss, epistaxis, battles sign (post auricular bruising), vertigo and nystagmus
What is Bell’s palsy?
Complete or partial paralysis of CN7, most likely caused by an infection
How does Bell’s palsy present?
No forehead sparing, eye drooping, increased sound sensitivity, mouth drooping, decreased taste
Why does an acoustic neuroma (vestibular schwannoma) affect cranial nerves 5, 7 and 8?
It grows on CNVIII, and compresses local structures such as CNV and CNVII
What is the general presentation of an acoustic neuroma?
Progressive Unilateral sensorineural hearing loss, tinnitus, dizziness (Facial pain, numbness, facial weakness, headaches, vomiting)
What is jugular foramen syndrome?
Paresis of CNIX, CNX, CNXI (and sometimes CNXII)
What are the symptoms of jugular foramen syndrome?
dysphonia, soft palate dropping, uvula deviation towards normal side, dysphagia, loss of taste from back of tongue, decrease parotid secretion, loss of gag reflex, sternocleidomastoid and trapezius paresis
What are the nuclei associated with the parasympathetic nervous system?
Visceral oculomotor (edinger-westphal) nucleus (CNIII)
Superior salivatory nucleus (CNVII)
Inferior salivatory nucleus (CNIX)
Dorsal vagal nucleus (CNX)
Do cranial nerve nuclei contain both sensory and motor components?
No, it is one or the other
How many cranial nerve nuclei are in the brainstem?
18 main ones
Which nuclei are general somatic efferent?
Oculomotor, trochlear, abducens, hypoglossal
Which nuclei are special visceral efferent?
motor nucleus of trigeminal, nucleus of facial nerve, nucleus ambiguus (parasympathetics to heart, laryngeal muscles)
Which nuclei are general visceral efferent?
accessory oculomotor nucleus (Edinger-Westphal), salivatory nuclei, dorsal vagal nucleus
Which nuclei are general and special visceral afferent?
Nuclei of the solitary tract, commissural nucleus of vagus, gustatory nucleus
Which nuclei are general somatic afferent?
principal sensory nucleus of the trigeminal nerve, spinal nucleus of trigeminal nerve, mesencephalic nucleus of trigeminal nerve
Which nuclei are special somatic afferent nuclei?
Cochlear and vestibular nuclei
Where is the oculomotor nucleus?
Superior aspect of the midbrain at the level of the superior colliculus, next to the cerebral aqueduct
Where is the trochlear nucleus?
Lower midbrain at the level of the inferior colliculus, lies anterior to the cerebral aqueduct
Where is the abducens nucleus?
in the lower pons, deep to the facial colliculus
Where is the hypoglossal nucleus?
Upper medulla, near the midline in the floor of the 4th ventricle
What do the special visceral efferent nuclei supply?
Skeletal muscle from the branchial arches
Where is the motor nucleus of the trigeminal nerve?
In the upper pons, dorsally, medial to the main sensory nucleus of the trigeminal nerve
Where is the nucleus of the facial nerve?
In the lower pontine tegmentum, anterolateral to the nucleus of the abducens nerve, fibres loop around abducens nucleus and form the facial colliculus
Where is the nucleus ambiguus?
In the medulla, deep in the reticular formation
What is the nucleus ambiguus?
A composite nucleus with fibres to glossopharyngeal, vagus and accessory
Where is the Edinger-Westphal nucleus?
In the midbrain
What does the Edinger-Westphal nucleus do?
Pupillary light reflex and accommodation (oculomotor parasympathetics)
Where do the salivatory nuclei lie?
In the dorsal part of the pons
What does the superior salivary nucleus do?
Sends fibres to facial nerve to innervate submandibular and salivary glands
What does the inferior salivary nucleus do?
Sends fibres to the glossopharyngeal nerve to innervate parotid gland
Where does the dorsal/motor nucleus of the vagus nerve lie?
It is a long nucleus that sits vertically in the medulla, deep to the vagal trigone
What does the nucleus solitarius do? (solitary nucleus)
Receives input from visceral sensations from vagus and glossopharyngeal nerves
Which nerves synapse in the gustatory nucleus?
Facial, glossopharyngeal and vagus nerves
What does the mesencephalic nucleus of the trigeminal nerve do?
Muscles of mastication
How does an upper motor neuron hypoglossal paralysis differ to a lower deficit?
Upper: tongue deviates to opposite side, mild weakness
Lower: tongue deviates to side of lesion, atrophy, fasciculation
(left sides tongue muscle contraction causes right sided tongue movement, genioglossus only receives info from contralateral cerebral cortex)