6-Cranial Nerves brainscape Flashcards
Bell’s Palsy
Inflammation of the facial nerve near hte stylomastoid foramen, compression of nerve
Bitemporal hermianopsia
loss of vision of one half of hte visual side of both eyes
Branches of V1
Nasal Lacrimal Frontal –> supratrochlear and supraorbital
Branches of V2
Zygomaticofacial Zygomaticotemporal Infraorbital
Branches of V3
Mental Buccal Auricotemporal Lingual
Branches of VII (Intra & Extracranial)
Intracranial : 1) Greater Petrosal (parasymp to glands & sinuses) 2) Nerve to stapedius 3) Chorda tympani (to glands and SA for taste) Extracranial: distal to the stylomastoid foramen To Zanzibar By Motor Car Temporal Zygomatic Buccal Marginal Cervical
Branchial Motor- Function & Nerves
Motor innervation to skeletal muscles derived from pharyngeal arch mesoderm V- Trigeminal VII- Facial IX- Glossopharyngeal X- Vagus
Ciliary Ganglion- Preganglionic Parasympathetic, Postganglionic Sympathetic, General Sensory
Preganglionic Parasympathetic: Oculomotor (III) Postganglionic Sympathetic: from the internal carotid General Sensory: Opthalamic (V1) Target Organ: Ciliaris, Sphincter pupillae, Iris
Components of the Ganglia of the H/N
1) Motor Root (GVE parasympathetic III, VII, IX or X presynaptic root that synapses there, postsynaptic emerges) 2) Sensory Root (GSAfrom one of the main divisions of CN V) 3) Postganglionic sympathetic root
Consensual pupillary action
shine light in a pupil, the other one constricts with it
Cranial Accessory Nerve
Motor innervation to the larynx, palate, and cardiac branches
Damage to VII
*Most common injured cranial nerve *Paralysis of ipsilateral side *Loss of taste to anterior 2/3 of tongue *Alter secretions of lacrimal and salivary glands *Loss of corneal reflex
Diplopia
double vision
Direct Pupillary Action
shine light into pupil, that pupil constricts
Divisions of the Oculomotor nerve
Superior - Levator Palpebrae Superioris & Superior Rectus Inferior- Inferior Rectus, Inferior oblique, medial rectus & carries preganglionic fibers to the ciliary ganglion
Extraoclear Eye Muscles
Superior Oblique (IV) Inferior Oblque (III) Superior Rectus (III) Superior Rectus (III) Inferior Rectus (III) Medial Rectus (III) Lateral Rectus (VI)
Foramens of CN VII
Internal acoustic Meatus & Stylomastoid foramens
From what region does the parasympathetic of the autonomic ganglia in HN arise?
Craniosacral region (the parasympathetic cranial nerves)
From what region does the sympathetic innervation of the HN arise?
Thoracolumbar region
Function of Auricular branch of Vagus Nerve
General sensory to auricle, external acoustic meatus, and tympanic membrane
Function of CN III
Somatic Motor: Superior, medial, inferior rectus, inferior oblique, levator palpebrae) Visceral Motor:(parasympathetic) ciliaris & sphincter papillae (accommodation of the lens & pupil constriction)
Function of CN IV
Somatic Motor- to superior oblique muscle
Function of CN IX
Visceral Afferent: from carotid body and sinus, posterior 1/3 of tongue, pharynx, soft palate, middle ear Special Sensory: From posterior 1/3 of tongue Visceral Efferent: parasymp to parotid gland BE: to stylopharyngeus muscle
Function of CN VI
Innervates lateral rectus muscle
Function of CN X
Somatic Afferent: from external acoustic meatus and skin posterior to ear Visceral Afferent: from aortic body & aortic arch receptors, dura of posterior cranial fossapharynx, larynx, viscera of thorax & most of abdomen Special: Taste from epiglottis Visceral Efferent: parasymp to pharynx, larynx, viscera of thorax and most of abdomen BE: to palatoglossus, most of muscles of pharynx and palate, and laryngeal muscles
Function of External Laryngeal branch of Vagus Nerve
Motor innervation to cricothyroid muscle
Function of Internal Laryngeal branch of Vagus Nerve
General sensory to mucosa of larynx above the vocal cords General sensory and taste to the posterior part of tongue and epiglottis
Function of Pharyngeal branch of Vagus Nerve
*Motor innervation to all pharyngeal muscles except the Stylopharyngeus (IX) *Motor innervation to all palatine muscles, except the tensor veli palatini (V3)
Function of Recurrent Laryngeal branch of Vagus Nerve
General sensory to the larynx below the vocal cords Motor to laryngeal muscles, except cricothyroid
Function of the nerve to the carotid body branch of the vagus nerve
sensory innervation to the carotid body, sensor of blood O2 content
Function of V3 Pharyngeal Innervation
*Muscles of mastication 1) Masseter 2) Temporalis 3) Medial pterygoid 4) Lateral ptyerigoid*Tensor tympani *Tensor veli palatini *Anterior belly of digastric *Mylohyoid
Function of VII
Somatic Afferent: External auditory meatus Special: Taste on anterior 2/3 of tongue Visceral Efferent: Parasympathetic: to sublingual and submandibular glands, lacrimal gland, and mucous glands BE: muscels of facial expression, stapedius, posterior belly of digastric, and sylohyoid
Function of XII
Somatic Efferent: To all intrinsic and extrinsic muscles of the tongue except the palatoglossus
General Sensation and Taste innervation of the tongue
CN X = Internal laryngeal specifically
General Somatic Afferent nerves - Function & Nerves
Perception of touch, pain, temperature V- Trigeminal VII- Facial IX - Glossopharyngeal X - Vagus
General Somatic Efferent nerves- Function & Nerves
Motor innervation to voluntary muscles III- Oculomotor IV- Trochlear VI- Abducent XI- Accessory XII- Hypoglossal
General Visceral Afferent - Function & Nerves
Sensory input from viscera IX- Glossopharyngeal X- Vagus
General Visceral Efferent- Function & Nerves
Motor innervation to smoth muscle, heart and glands Oculomotor (III) Facial (VII) Glossopharyngeal (IX) Vagus (X)
Herpes Zoster
Shingles- virus remains latent in sensory neurons of the trigeminal ganglion
Homonymous hemianopsia
visual loss in similar fields
how does the facial nerve exit the cranium
stylomastoid foramen
How to test CN X
Uvula will deviate away from afflicated side due to unopposed action of levator veli palatini (
How to test CN XII
1) Articulation of speech 2) Atrophy of tongue 3) Stick out tongue –> Deviation to affected side
Injury to the Trigeminal Nerve
1) Loss of corneal reflex 2) Paralysis of muscles of mastication, jaw deviates to affected side 3) Trigeminal neuralgia (tic douloureaux) - pain V1 & V2 area of face
Lesion to abducens
eye will deviate towards the nose (paralysis of lateral rectus)
Lesion to the Trochlear Nerve
Strabismus- person cannot look inferolaterally –> double vision when looking down
Lesions of the Oculomotor Nerve
*Dilated pupil- due to damage to parasymp to sphincter, dilator pupillae unopposed *“down and out” gaze - unopposed SO & LR muscles *Ptsosis- loss of levator palpebrae *Loss of accommodation reflex (paralysis of ciliary muscle)
Location of the ciliary ganglion
posterior orbit of the eye, between the optic nerve and the lateral rectus
Location of the Otic Ganglion
immediately inferior to the foramen ovale, between the tensor veli palatini muscle and Mandibular nerve (V)
Location of the Pterygopalatine Ganglion
Pterygo-palatine fossa, hanging form Maxillary Nerve (V2)
Location of the submandibular ganglion
Above the deep portion of the submandibular gland, on hyoglossus muscle, hanging from the lingual nerve (from V3)
Location of the trigeminal ganglion
apex of the petrous part of the temporal bone in the middle cranial fossa
Muscles of mastication
Masseter Temporalis Medial Pterygoid Lateral Pterygoid
Mydriasis
dilation of the pupil
Otic Ganglion- Postganglionic Sympathetic, Preganglionic Parasympathetic, General Sensory
Preganglionic Parasympathetic- Tympanic nerve from Lesser Petrosal Nerve (IX) Postganglionic Sympathetic: general from external carotid General Sensory: Mandibular (V3)
Parasympathetic Ganglion in the HN
Ciliary Submandibular Pterygopalatine Otic
Pterygopalatine Ganglion- Postganglionic sympathetic, preganglionic parasympathetic, general sensory
Preganglionic Parasympathetic: Greater Petrosal Nerve (VII) Postganglionic Sympathetic: Deep petrosal nerve (from internal carotid) General Sensory: Maxillary (V2)
Special Afferent - Function & Nerves
Smell, Taste, Vision, Hearing, Balance I, II, VII, VIII, IX, X
Spinal Accessory Nerve
SCM & Trap
Strabismus
affected eye moves in different directions without proper control due to a cranial nerve lesion that paralyzes the extraoclear muscles
Submandibular Ganglion- Preganglionic parasympathetic, Postganglionic Sympathetic, General Sensory
Preganglionic Parasympathetic: Chorda tympani (VII) Postganglionic Sympathetic: from external carotid General Sensory: Lingual nerve (V3)
Target of the Pterygopalatine Ganglion
Lacrimal gland, nasal cavitiy, palate, pharynx *Produces hayfever symptoms, wine tasting, tearing up
Target Organ of CIliary Ganglion
*Sphincter pupillae *Ciliaris muscle
Target Organ of the Otic Ganglion
Parotid Gland for salivation
Target Organs of the Submandibular Gland
Submandibular & Sublingual glands
Terminal Branches of the Parotid Plexus
Temporal Zygomatic Buccal Mandibular Cervical (also a posterior auricular branch)
Test for CII
Pupillary Light Reflex Afferent = CII, Efferent = CIII
Test for CN XI
Inability of a patient to elevate shoulder against resistance (do not test for cranial accessory)
Testing C1
Smell test with normal compound (ie coffee) one nostril at at ime
Testing CN VIII
*Tuning fork in front of ear, then in front of bone. If hear in against bone then nerve is intact *Or stand to see if they sway and lose balance
Testing CV
Touch: Forehead (V1) Cheek (V2) Chin (V3) Corneal Reflex Afferent CV, Efferent CII
Testing CVII
Muscles of fascial expression Taste on anterior 2/3 of tongue
Trigeminal Ganglion
Sits at apex of the petrous part of the temporal bone in the middle cranial fossa (Meckel’s Cave) in the dura mater *Contains cell bodies for sensory neurons in the trigeminal nerve
V3 Muscle Supply
Muscles of Mastication Anterior Belly of Digastric Mylohoid Tensor veli palatini Tensor tympani
VII motor innervation
muscles of facial expression Posterior belly of digastric stapedius
What are the components of the cavernous sinus?
III (Oculomotor) IV (Trochlear) V1, V2 (Trigeminal) VI (Abducens) Internal Carotid artery
What are the cranial nerves of the forebrain?
CN I & CN II
What are the cranial nerves of the medulla oblongata?
CNs IX, X, XI, XII
What are the cranial nerves of the midbrain?
CNs III & IV
What are the cranial nerves of the Pons?
CNs V, VI, VII, VIII
What are the functions (motor, sensory, both) of the trigeminal branches?
V1 & V2 = sensory, V3= mixed
What can injure the trigeminal nerve?
Trauma Tumors Aneurysms Meningeal infections
What CN are responsible for muscular contractions associated with gagging?
CN IX and X
What is the only nerve that does not exit the cranial cavity?
CN VIII
What is the only nerve to exit from the dorsal (posterior) surface of the brainstem?
Trochlear
What is the path of the vagus out of the skull?
Emerges from jugular foramen and descends within carotid sheath, behind and between internal jugular vein and internal/common carotrid artery
What is the result of a lesion to the right optic nerve
blindness in the right eye
What is the result of a vision in the optic chiasm?
Reduction in peripheral vision (ie Bitemporal hermianopsia)
What ist he largest cranial nerve?
Trigeminal
What supplies the cornea?
V1
What will be the effect of a lesion on the right optic tract?
Loss of vision from left visual field on both sides (Left homonymous hermianopsia)
Where does CNVIII emerge?
Junction of the pons & medulla
Where does frontal branch of V1 exit the skull?
Supraorbital foramen/notch
Where does the abducens nerve emerge from the brainstem?
Between the pons and medulla
Where does the facial nerve exit the cranium?
Stylomastoid foramen
Where does V2 exit the cranial cavity?
Intraorbital foramen
Where does V3 exit the cranium
Mental Foramen
Where will damage to the facial nerve at teh stylomastoid foramen manifest in paralysis?
The ipsilateral side (same side)
Which cranial nerve does not originate from the brain?
Accessory (XI)
Which nerve has the longest cranial course? what are the implications of this?
Abducens –> can become stretched when intracranial pressure rises
Which nerves have parasympathetic nature?
III (Oculomotor) VII (Facial) IX (Glossopharyngeal) X (Vagus)
