Head Anatomy 2 Flashcards
What are intra-cranial causes of facial nerve palsy?
-middle/ inner ear infection
What are extra-cranial causes of facial nerve palsy?
-forceps delivery
-viral infection
-parotid gland pathology
What is Bell’s palsy?
It’s a condition causing paralysis of facial muscles by affecting the facial nerve, cause is unknown.
Can last up to 6 months and may be due to:
-Autoimmune/ inflammatory causes
-infection
-diabetes
What are the symptoms of intra-cranial facial nerve palsy?
Parasympathetic:
Dry eyes (greater petrosal nerve)
Dry mouth + altered taste in anterior 2/3rds (chorda tympani)
Motor:
Hyperacusis (nerve to stapedius)
What are the symptoms of EXTRA-cranial facial nerve palsy?
Motor:
Paralysis of facial muscles = drooping face, drooling
Damage to which 2 nerves can cause hyperacusis and what are the muscles they supply?
Trigeminal = tensor tympani
Facial/ nerve to stapedius = stapedius
How can you tell the difference between a stroke and Bell’s palsy?
Stroke (UMN):
-Forehead spared (can wrinkle)
-Facial droop on opposite side of lesion
Bell’s palsy:
-No forehead sparing
-facial droop on same side as lesion
-other sx present = dry eyes & mouth, loss of taste in ant 2/3rds tongue
What are the structures found passing through the parotid gland?
Facial nerve
Retro mandibular vein
External carotid artery
(Order= superficial to deep)
What nerve is damaged during a parotidectomy?
Marginal mandibular branch of facial nerve
Describe where the incision would be for excision of submandibular gland?
4cm below the mandible
What are the structures that can be damaged during excision of the submandibular gland.
Marginal mandibular branch of CN7
lingual nerve
Hypoglossal nerve
What are the names of the ducts of the
-parotid gland
-submandibular gland
Parotid= stensons duct
Submandibular = whartons duct
Describe the clinical symptoms for a patient presenting with vestibular schwannoma
Hearing loss + tinnitus
Ataxia
Facial paresis
What cranial nerves are found at the cerebello-pontine angle?
CN 5, 7, 8
Where does CN9 provide sensation to?
General sensation & taste to posterior 1/3rd of tongue
Afferent limb of gag reflex
What muscle(s) does CN9 innervate?
Stylopharyngeus
What is the parasympathetic function of CN9?
Controls secretions from parotid gland
What surgery can cause damage to the glossopharyngeal nerve?
What sx would they present with?
Removal of tonsils
Sx:
-mild dysphasia
Loss of taste and sensation in posterior 1/3rd tongue
Ear pain
Patient has a surgery in the oropharyngeal area and has otalgia post-op.
How can you determine which nerve has been injured to cause the otalgia?
Site of surgery:
Site at tongue base= CN9
Site at back of throat= CN10
Both can cause ear pain if damaged
What are the branches of the vagus nerve that supply the larynx and described their anatomical path.
Recurrent laryngeal nerves
Both = exit skull via jugular foramen, enter carotid sheath
Right:
In front of SCJ
Loops around right subclavian artery
Travels back up to larynx
Left:
Travels down to arch of aorta and loops back up to larynx
What are the laryngeal muscles innervated by vagus nerve?
Recurrent laryngeal nerve innervates:
-transverse & oblique arytenoids
-posterior & lateral cricoarytenoids
Thyroarytenoids
Vocalis
Which muscle in the tongue is innervated by CN10
Palatoglossus
What are the areas the vagus provides sensation to?
-external auditory meatus
-larynx
-pharynx
Which laryngeal muscle is NOT supplied by the recurrent laryngeal nerve?
Which nerve supplies it?
Cricothyroid
Superior laryngeal nerve
What are the parasympathetic functions of CN10?
-reduces resting HR
-increases gastric secretions
Increased gastric emptying
-increased gastric acid production
Uvula is deviated to which side in left sided vagus nerve palsy
Right sided deviation
What are the afferent and efferent limbs of the gag reflex?
Afferent = CN9
Efferent= CN 10
What are the landmarks for the CN11?
1/3rd of way down SCM
2/3rd of way down trapezius
What are the symptoms in CN11 palsy?
Weakness in shrugging ipisilateral shoulder
Weakness in turning neck to contra lateral side
What nerve palsy causes tongue deviation?
Deviation is to which side?
Hypoglossal nerve
Deviates TO side of lesion
What are the cranial nerves found in the
-midbrain
-pons
-medulla
-midbrain= CN3, 4
-pons = CN 5, 6, 7, 8
-medulla= CN 9, 10, 11, 12
What nerve innervates the following ear parts
-Tragus
-lobule
-back of ear
-concha
-tragus= auriculotemporal
-lobule= great auricular
-back= lesser occipital
-concha= vagus +/-facial nerve
What nerves innervate the muscles of the tongue?
Hypoglossal except for palatoglossus (CN10)
What are the intrinsic muscles of the tongue?
-superior longitudinal
-inferior longitudinal
Vertical
Transverse
What are the extrinsic muscles of the tongue and their actions?
-genioglossus (stick out
-palatoglossus (up)
-styloglossus (up)
-hyoglossus (down)
In the following reflexes, name the Afferent and efferent limbs!
-corneal
