4: Cranial Nerves & Autonomics of the H & N Flashcards
What are the 5 fibre types of Cranial Nerve?
- Motor fibres to voluntary (striated) muscle
- Motor fibres innervating involuntary muscles and glands
- Sensory (afferent) fibres: General transmission from skin and mucus membrane
- Sensory (afferent) fibres carrying sensation from viscera
- Sensory (afferent) fibres transmit unique SPECIAL sensory sensation
What fibre type is the Olfactory Nerve (CN 1)?
Special Sensory (5)
What does the Olfactory Nerve (CN 1) control?
Sense of smell
Where does the Olfactory Nerve (CN 1) originate?
Cerebrum
What is the Cranial exit of the Olfactory nerve (CN 1)?
Cribriform plate
How is the Olfactory Nerve (CN 1) tested?
Testing smelling
What fibre type is the Optic Nerve (CN 2)?
Special Sensory (5)
What is the origin of the Optic Nerve (CN 2)?
Cerebrum
What is the cranial exit of the Optic nerve (CN 2)?
Optic canal
What is the function of the Optic nerve (CN 2)?
Vision
How is the Optic nerve (CN 2) tested?
Pupil responses to light
What fibre type is the Occulomotor Nerve (CN 3)?
Motor (1) & (2)
To Voluntory + Invol muscles
What is the origin of the Occulomotor Nerve (CN 3)?
Midbrain of brainstem
What is the cranial exit of the Occulomotor Nerve (CN 3)?
Superior Orbital Fissure
What is the function of the Occulomotor Nerve (CN 3)? ( 2 things)
- Motor (1 Vol): Extrinsic eye muscles & levator palpebrae
- Motor (2 Invol): Pupillary sphincter
How is the Occulomotor Nerve tested?
Test movements of eye
What fibre type is the Trochlear Nerve (CN 4)?
Motor (1 Vol)
What is the origin of the Trochlear Nerve (CN 4)?
Midbrain of brainstem
What is the cranial exit of the Trochlear Nerve (CN 4)?
Superior orbital fissure
What is the function of the Trochlear Nerve (CN 4)?
Sup oblique muscle of eye
How is the Trochlear Nerve (CN 4) tested?
Test movements of eye
What is the fibre type of the Trigeminal Opthalmic Nerve (CN V1)?
Motor (2 Invol)
What is the origin of the Trigeminal Opthalmic Nerve (CN V1)?
Pons
What is the cranial exit of the Trigeminal Opthalmic Nerve (CN V1)?
Sup orbital fissure
What is the function of the Trigeminal Opthalmic Nerve (CN V1)?
Scalp, forehead and nose
What is the fibre type of the Trigeminal Maxillary Nerve (CN V2)?
Motor (2 Invol)
What is the origin of the Trigeminal Maxillary Nerve (CN V2)?
Pons
What is the cranial exit of the Trigeminal Maxillary Nerve (CN V2)?
Foramen rotundum
What is the function of the Trigeminal Maxillary Nerve (CN V2)? (6 things)
- Cheeks
- lower eyelid
- Nasal mucosa
- Upper lip
- upper teeth
- palate
What is the fibre type of the Trigeminal Mandibular Nerve (CN V3)?
Motor (2 Invol)
What is the origin of the Trigeminal Mandibular Nerve (CN V3)?
Pons
What is the cranial exit of the Trigeminal Mandibular Nerve (CN V3)?
Foramen ovale
What are the functions of the Trigeminal Mandibular Nerve (CN V3)? (4 things)
- Ant 2/3 tongue
- Skin over mandible
- lower teeth
- muscles of mastication
What is the fibre type of the Abducens Nerve (CN 6)?
Motor (1 Vol)
What is the origin of the Abducens Nerve (CN 6)?
Pontine - Medulla junction
What is the cranial exit of the Abducens Nerve (CN 6)?
Sup orbital fissure
What is the function of the Abducens Nerve (CN 6)?
Lactal rectus
How is the Abducens Nerve (CN 6) tested?
Test movements of eye
What is the fibre type of the Facial Nerve (CN 7)?
All
What is the origin of the Facial Nerve (CN 7)?
Pontine - Medulla junction
What is the cranial exit of the Facial Nerve (CN 7)?
Internal acoustic meatus
What is the function of the Facial Nerve (CN 7)? (6 things)
- Part of external ear sensation
- Muscles of facial expression
- Mucous glands of mouth + nose
- Taste from ant 2/3 tongue
- Palate
- Lacrimal / submandibular / sublingual glands
How is the Facial Nerve (CN 7) tested? (3 things)
- Raise eyebrows
- Close eyes vs resistance
- Puff cheeks and reveal teeth
What is the fibre type of the Vestibulocochlear Nerve (CN 8)?
Sensory (5)
What is the origin of the Vestibulocochlear Nerve (CN 8)?
Pontine - medulla junction
What is the cranial exit of the Vestibulocochlear Nerve (CN 8)?
Internal acoustic meatus
What is the function of the Vestibulocochlear Nerve (CN 8)?
Hearing & balance
How is the Vestibulocochlear Nerve (CN 8) tested?
Rinne’s Test
- tuning fork on mastoid / ear
- Should be louder @ EAR
What is the fibre type of the Glossopharyngeal Nerve (CN 9)?
All of them
What is the origin of the Glossopharyngeal Nerve (CN 9)?
Medulla oblongata
What is the cranial exit of the Glossopharyngeal Nerve (CN 9)?
Jugular foramen
What is the function of the Glossopharyngeal Nerve (CN 9)? (6 things)
- Ext ear
- Middle ear cavity
- Stylophayngeus
- Parotid gland
- Taste and sensation of post 1/3 tongue
- Carotid body & Sinus
How is the Glossopharyngeal Nerve (CN 9) tested?
Gag reflex
What is the fibre type of the Vagus Nerve (CN 10)?
All of them
What is the origin of the Vagus Nerve (CN 10)?
Medulla oblongata
What is the cranial exit of the Vagus Nerve (CN 10)?
Jugular foramen
What is the function of the Vagus Nerve (CN 10)? (4 things)
- Ext ear
- Taste from epiglottis region of tongue
- Larynx + pharynx
- Thoracic + abdominal viscera (organs)
How is the Vagus Nerve (CN 10) tested?
Patient says aaah, check uvula (hanging tonsil thingy at back of throat) before and after
What is the fibre type of the Spinal Accessory Nerve (CN 11)?
Motor (1 Vol) & (2 Invol)
What is the origin of the Spinal Accessory Nerve (CN 11)?
Medulla oblongata
What is the cranial exit of the Spinal Accessory Nerve (CN 11)?
Jugular foramen
What is the function of the Spinal Accessory Nerve (CN 11)? (2 things)
- Trapezius
- SCM
How is the Spinal Accessory Nerve (CN 11) tested?
Get patient to shrug shoulder and turn head vs resistance
What is the fibre type of the Hypoglossal Nerve (CN 12)?
Motor (1)
What is the origin of the Hypoglossal Nerve (CN 12)?
Medulla oblongata
What is the cranial exit of the Hypoglossal Nerve (CN 12)?
Hypoglossal canal
What is the function of the Hypoglossal Nerve (CN 12)?
Instrinsic + Extrinsic tongue muscles
How is the Hypoglossal Nerve (CN 12) tested?
Stick tongue out
if tongue deviates to one side = weaking of muscle on one side
What are the causes and consequences of CN 1 damage? (1:3 things)
Cause
cribriform plate
Consequences
- Anosmia (loss of smell)
- Rhinorrhoea (CSF leak from nose)
- Meningitis
What are the causes and consequences of CN 2 damage? (1:2 things)
Cause
optic canal
Consequences
- Loss of pupillary constriction
- Raised Intracranial pressure / blood loss from central artery of retina → pressure on optic pathway → pupilloedema (optic disc swelling) → visual defects
What are the causes and consequences of CN 3 damage? (3:3 things)
Causes
- Cavernous sinus thrombosis
- Aneurysm of post cerebral / sup cerebellar artery
- Raised intracranial pressure
Consequences
- Dipoplia (double vision)
- Ptosis (drooping eye lid)
- Dilated pupil with NO pupillary light reflex
What are the consequences of CN 4 damage? (2 things)
Consequences
- Eyeball adducted and sup rotated
- Dipoplia (double vision)
What are the causes and consequences of CN 5 damage? (6:4 things)
Causes
- Trauma
- Tumour
- Aneurysm
- Meningeal infections
- Herpes zoster infection
- Trigeminal neuralgia (fx sensory root of CN V)
Consequences
- Muscles of mastication paralysis
- NO sensation to face
- NO corneal & sneezing reflexes
- Excruciating pain to max and mand divisions of nerve (if trigeminal neuralgia)
What are the causes and consequences of CN 6 damage? (4:2 things)
Causes
- Raised intracranial pressure
- Aneurysm to cerebral arterial ring @ brain base
- Increased pressure in cavernous sinus from atherosclerotic changes
- Septic thrombus in cavernous sinus
Consequences
- Eye adduction
- Dipoplia (double vision)
What are the causes and consequences of CN 7 damage? (2:2 things)
Causes
- Knife / gun injury
- # temporal bone
Consequences
- Facial nerve palsy
- Inf face musclular paralysis on contralateral side
What are the causes and consequences of CN 8 damage? (3:3 things)
Causes
- Skull #
- Ear infection
- Central lesions
Consequences
- Vertigo (everything spinning)
- Tinnitus (ringing ears)
- Hearing impairement
What are the consequences of CN 9 damage? (3 things)
Consequences
- Dysphagia (difficulty swallowing)
- Blood pressure problems
- Parotid gland secretion problems
What are the causes and consequences of CN 10 damage? (4:4 things)
Causes
- Arch of aorta aneurysm
- Thyroid / larynx cancer
- Enlarged mediastinal lymph nodes
- Thyroid surgery
Consequences
- Dysphagia (difficulty swallowing)
- Inspiratory stridor (breath in → collapse of tissue above vocal cords)
- Hoarseness
- Loss of cricothyroid muscle → aphonia
What are the causes and consequences of CN 11 damage? (1:1 things)
Causes
- Surgery
Consequences
- NO SCM / trapezius innervation
What are the consequences of CN 12 damage? (2 things)
Consequences
- Tongue atrophy (wasting)
- Tongue deviating to paralysed side of tongue
Where do PS nerves originate?
Cranial sacral source
What is the outflow of PS nerves provided by?
CN 3, 7, 9, 10
S2-4
Where do S NS nerves originate from?
Thoracolumbar region
What is the outflow of S NS nerves provided by?
T1 - L2
How do S NS nerves send fibres to tissue?
Nerves synapse with Pre-ganglionic neurone → post synaptic neurones → send fibres to target tissue
How do Symphathetic Post ganglionic fibres reach their targets in H & N?
By “hitch-hiking” on arterial system
Where is the Superior Cervical Ganglion?
@ level of C1 & C2
How do the post-synaptic fibres of the Superior Cervical Ganglion travel?
“Hitch-hike” on Internal & External Carotid Arteries
What do the Post-synaptic fibres of the Superior Cervical Ganglion innervate?
Trigeminal dermatomes
Where is the Middle Cervical Ganglion?
@ level of C6
How do the post-synaptic fibres of the Middle Cervical Ganglion travel?
“Hitch-hike” on inferior thyroid artery
What do the post-synaptic fibres of the Middle Cervical Ganglion innervate? (4 things)
- Trachea
- Lower oesophagus
- Lower larynx
- Laryngopharynx
Where is the Inferior Cervical Ganglion?
@ level of C7
How do the post-synaptic fibres of the Inferior Cervical Ganglion travel?
“Hitch-hike” on Vertebral artery
Where do PS pre-ganglionic axons synapse? (2 things)
- Autonomic ganglia
OR
- Walls of target organ
What are the 4 PS ganglia and their associated CN?
- Ciliary ganglion: CN 3
- Pterygopalatine g: CN 7
- Submandibular g: CN 7
- Otic g: CN 9
Where does the Ciliary ganglion lie?
Orbital cavity
What is the route of the PS fibres of the Ciliary ganglion?
CN3 → Ciliary muscle + Pupillae of iris
What is the route of the Symp fibres of the Ciliary ganglion?
Sup Cervical Ganglion → Dilator pupillae + eye blood vessels
What is the route of the Sensory fibres of the Ciliary ganglion?
Pass through eyeball uninterrupted
Where does the Pterygopalatine ganglion lie?
Pterygopalatine fossa
What is the route of the PS fibres of the Pterygopalatine ganglion?
Greater petrosal nerve → Lacrimal gland
What is the route of the Symp fibres of the Pterygopalatine ganglion?
Sup Cervical Ganglion – ICA plexus →
- Blood vessels of nasal cavity
- Palate
- Superior parts of pharnyx
What is the route of the Sensory fibres of the Pterygopalatine ganglion?
From Maxillar n
passed uninterrupted
Where does the Submandibular ganglion lie?
Surface of hypoglossus muscle
What is the route of the PS fibres of the Submandibular ganglion?
CN 12 – chorda tympani branch →
- Unite with lingual nerve
- Supplies submandibular and sublingual
What is the route of the Symp fibres of the Submandibular ganglion?
Sup Cervical Ganglion – CN 12 plexus → submandibular & sublingual nerve
What is the route of the Sensory fibres of the Submandibular ganglion?
From lingual nerve
passes uninterrupted
Where does the Otic ganglion lie?
Inf to foramen ovale
What is the route of the PS fibres of the Otic ganglion?
CN 9 →
- Parotid gland
- Post 1/2 of tongue
What is the route of the Symp fibres of the Otic ganglion?
Sup Cervical Ganglion → Parotid gland
What is the route of the Sensory fibres of the Otic ganglion?
To post 1/3 tongue
