Nerves Flashcards
Greater occipital nerve
Sensory Branch of dorsal ramus of C2
Emerges from between C1 and C2, inferior to obliquus capitis inferior
Sensation from the back of the head
Least (3rd) occipital nerve
Sensory branch of dorsal ramus of C3
Inferior to greater occipital nerve
Sensation from posterior of head and neck
How does the vagus nerve (CN X) travel through the neck?
Between the common carotid artery and internal jugular vein within the carotid sheath
How does the hypoglossal nerve (CN XII) travel through the neck?
Deep to posterior belly of digastric - between internal carotid artery and internal jugular vein - crosses over external carotid artery to loop anteriorly - dives between mylohyoid and hyoglossus muscles (traveling with lingual artery)
Where is the cervical portion of the sympathetic trunk found?
Deep to contents of carotid sheath
Against pre-vertebral muscles
Name the ganglia typically found in the cervical portion of the sympathetic trunk
Superior
Middle
Inferior
Vertebral
Cervicothoracic (stellate) ganglion
The common fusing of the inferior cervical ganglion and the first thoracic ganglion of the sympathetic trunk
Typically posterior to subclavian artery
Ansa subclavia
Thin loop of sympathetic fibers that travel anterior to subclavian artery
Connect stellate ganglion to vertebral ganglion
Carotid plexus
Sympathetics traveling above superior cervical ganglion
Travel with the carotid vessels
Superior cervical gangion
Sympathetics to head
Middle cervical ganglion
Sympathetics to heart and lungs
Inferior cervical ganglion
Sympathetics to heart and lungs
Horner’s syndrome
Lesion of sympathetic trunk in neck
Causes: stroke, neck trauma, carotid artery injury, Pancoast tumors (top of lungs), cluster headaches
Symptoms:
- miosis (contraction of pupil)
- ptosis (drooping of eyelid)
- anhidrosis (decreased sweating face/neck)
Branchial fistula
Abnormal canal resulting from the persistence of remnants of the 2nd pharyngeal pouch
Passes through subcutaneous tissue, platysma, fascia of neck to enter carotid sheath
Passes between internal and external carotid arteries to tonsillary sinus
Usually travels along anterior of SCM
Saliva may drip from fistula - infection
How does the brachial plexus course through the neck?
Travels between anterior and middle scalene - between clavicle and first rib
How does the phrenic nerve course through the neck?
C3, C4, C5
Runs anteriorly to anterior scalene - enters thorax - runs along pericardium - diaphragm
How does the accessory nerve (CN XI) course through the neck?
C1-C6
Enters skull through foramen magnum - leaves skull through jugular foramen - deep to levator scapulae to trapezius
Innervates SCM and trapezius
How does the olfactory nerve (CN I) pass through the skull?
Olfactory foramina (ethmoid bone)
How does the optic nerve (CN II) pass through the skull?
Optic canal (sphenoid bone)
How does the oculomotor nerve (CN III) pass through the skull?
Superior orbital fissure (sphenoid bone)
How does the trochlear nerve (CN IV) pass through the skull?
Superior orbital fissure (sphenoid bone)
How does the opthalmic division of the trigeminal nerve (CN V-1) pass through the skull?
Superior orbital fissure (sphenoid bone)
How does the abducens nerve (CN VI) pass through the skull?
Superior orbital fissure (sphenoid bone)
Which nerves pass through the superior orbital fissure of the sphenoid bone?
Oculomotor (III)
Trochlear (IV)
Opthalmic division of trigeminal (V1)
Adbucens (VI)
How does the maxillary division of the trigeminal nerve (CN V2) pass through the skull?
Foramen rotundum (sphenoid bone)
How does the mandibular division of the trigeminal nerve (CN V3) pass through the skull?
Foramen ovale (sphenoid bone)
How does the facial nerve (CN VII) pass through the skull?
Internal auditory meatus (temporal bone)
How does the vestibulocochlear nerve (CN VIII) pass through the skull?
Internal auditory meatus (temporal bone)
Which nerves pass through the internal auditory meatus of the temporal bone?
Facial (VII)
Vestibulocochlear (VIII)
How does the glossopharyngeal nerve (CN IX) pass through the skull?
Jugular foramen (between temporal and occipital bones)
How does the vagus nerve (CN X) pass through the skull?
Jugular foramen (between the temporal and occipital bones)
How does the accessory nerve (CN XI) pass through the skull?
Jugular foramen (between temporal and occipital bones)
Which nerves pass through the jugular foramen between the temporal and occipital bones?
Glossopharyngeal (IX)
Vagus (X)
Accessory (XI)
How does the hypoglossal nerve (CN XII) pass through the skull?
Hypoglossal foramen (occipital bone)
Anosmia
Loss of sense of smell
Can be caused by fracture of ethmoid bone
The medial retina of the eye receives information from the _______ and projects to the ______ of the brain
The medial retina of the eye receives information from the LATERAL and projects to the OPPOSITE side of the brain
The lateral retina of the eye receives information from the ________ and projects onto the _______ of the brain
The lateral retina of the eye receives information from the MEDIAL and projects onto the SAME SIDE of the brain
Trigeminal ganglion
Cell bodes of the unipolar sensory neurons of all 3 divisions of the trigeminal nerve (V)
In middle cranial fossa
Facial motor nucleus
Cell bodies of the neurons that innervate the muscles of facial expression
In brainstem
One on right and left sides
Have superior and inferior halves
The right facial motor nucleus innervates the muscles of facial expression on the _____ side of the face (and vice versa)
Right
Superior half of facial motor nucleus
Innervate muscles on superior half of face
Receives input from the cerebral cortex on BOTH sides of the brain (contralateral and ipsilateral)
- Receives most of it’s activation from the contralateral side
Inferior half of facial motor nucleus
Innervate muscles on the inferior part of face
Receives input from cerebral cortex on CONTRALATERAL side of brain
Lower motor neuron lesion
Lesion in neuron AFTER facial motor nucleus
Results in paralysis of muscles of facial expression on the same side as the lesion
Upper motor neuron lesion
Lesion of the axons coming from the cerebral cortex towards the contralateral facial motor nuclei - BEFORE they cross to the ipsilateral facial motor nuclei
NO activation of the contralateral inferior motor nucleus - paralysis of the inferior facial muscles on the opposite side of the lesion
Activation of superior motor nuclei on BOTH sides decreased, but mostly affects side contralateral to lesion - results in weakness of the superior facial muscles on BOTH sides
Bell’s Palsy
Inflammation of the facial nerve
Lower motor neuron lesion
What kind of lesion commonly result from a stroke?
Upper motor neuron lesion
Name the cutaneous nerve branches of the opthalmic division of the trigeminal nerve (V1)
Supraorbital Supratrochlear Infratrochlear External nasal Palpebral
Name the cutaneous nerve branches of the maxillary division of the trigeminal nerve (V2)
Infraorbital
Zygomaticotemporal
Zygomaticofacial
Name the cutaneous nerve branches of the mandibular division of the trigeminal nerve (V3)
Mental
Buccal
Auriculotemporal
Trigeminal neuralgia
Demyelination of the axons of the sensory nerves of trigeminal (V)
Middle aged, elderly
Sudden attacks of severe facial pain in response to otherwise painless stimuli
Lead to depression and suicide - psychological changes
Usually caused by pressure on sensory root of nerve near brainstem by artery
Herpes zoster
Viral infection that can cause lesions in cranial ganglia
20% cases in trigeminal (V)
Eruption of vesicles following course of affected nerve
Can affect any division - usually opthalmic (V1)
- corneal ulceration and scarring
Aka shingles
