Cranial Nerves- Target Structures Flashcards
Olfactory nerve- CN I- Peripheral Structures/ Distribution/ Function(s)
Olfactory mucosa of the nose-
primary olfactory neurons receive smell information and send to CNS via synapses with secondary neurons in the olfactory bulb —> axons out via olfactory tract to the medial temporal lobe
Optic nerve- CN II- Peripheral Structures/ Distribution/ Function(s)
retina of the eye
carries visual sensory information from the neural retina to the diencephalon & midbrain
Oculomotor nerve- Peripheral Structures/ Distribution/ Function(s)
motor
- superior ramus: levator palpebrae superioris, superior rectus
- inferior ramus: medial rectus, inferior rectus, inferior oblique
postganglionic parasympathetic axons–> travel with the short ciliary nerves (from CN V1) to innervate:
- Ciliary body- (lens accommodation)
- sphincter pupillae of iris- (constriction of the pupil)
trochlear - CN IV- target structures
superior oblique muscle
trigeminal, ophthalmic, CN V1- target structures/functions
CUTANEOUS INNERVATION: upper eyelid, forehead, skin over nose
lacrimal n.- sensory inn. of lacrimal gland, lateral upper eyelid
frontal n.-
- -supraorbital n- skin of forehead
- -supratrochlear n- skin over medial forehead
nasociliary
- -anterior ethmoidal n. - mucosa of frontal and ethmoidal sinuses, mucosa of nasal cavity, skin over nose
- -posterior ethmoidal n. - mucosa of sphenoid an ethmoidal sinuses, superior nasal cavity
- long ciliary n.- sensory inn of the eye, postganglionic sympathetic. innervation to dilator muscle of iris
- short ciliary n. - sensory inn. of eye, postganglionic sympathetic (pupil dilation) and postganglionic parasympathetic (cell bodies in ciliary ganglion) —> innervation of constrictor smooth muscle of the iris and ciliary bodies of the lens (VIA CN III)
- infratrochlear n. - sensory inn. of skin over bridge of nose
What cranial nerve provides preganglionic parasympathetic connection to the short ciliary n. of the nasociliary n. ? (branches of V1- ophthalmic nerve)
cranial nerve III- oculomotor nerve
CN V2 Trigeminal, maxillary- target structures/functions
CUTANEOUS INN- skin over zygomatic arch, upper lip, lateral nose, lower eyelid
posterior superior alveolar n.- sensory & postganglionic sympathetic innervation of the upper molars, and sensory, postganglionic sympathetic & postganglionic parasympathetic (via CN VII) innervation of maxillary sinus
infraorbital n.- sensory innervation of the skin of the upper lip, lateral nose and lower eyelid, and mucosa of upper lip
- -> middle superior alveolar
- -> anterior superior alveolar
zygomatic n. - sensory and post symp. innervation of skin over zygomatic arch
- -> innervation of lacrimal gland - pre para axons via CN VII synapse at cell body in pterygopalatine ganglion –> post para axons arise from ganglion
- -> communication with lacrimal n. of CN V1 via communicating branch
What cranial nerve provides preganglionic parasympathetic connection to the branches of CN V2- maxillary nerve (arising from the pterygopalatine ganglion)?
CN VII - FACIAL NERVE
CN V3- Trigeminal, mandibular n.- target structures/functions
CUTANEOUS INN: buccal skin, skin anterior to the ear, skin over chin and lower lip
SENSORY-
-meningeal branch: sensory & postganglionic sym. inn. of the dura mater
- buccal branch (long buccal nerve): sensory inn. of buccal skin and oral mucosa
- lingual n.- mucosa over ant. 2/3 tongue, floor of oral cavity, gingiva, TASTE- anterior 2/3 tongue, innervation of lingual, sublingual, and submandibular glands (connection with submandibular ganglion via CV VII)
- auriculotemporal n.- sensory innervation to TMJ, external auditory meatus, skin anterior to ear, post symp and post para. inn. of parotid gland (axons via CN IX from otic ganglion)
- inferior alveolar n.- inn. of lower teeth, buccal and labial gingiva
- -mental n. - skin over skin and lower lip
- -n. to mylohyoid- sensory inn. to mylohyoid and anterior digastric ms.
BRANCHIAL MOTOR (most provide sensory inn. to muscles)-
- deep temporal n. -sensory and motor inn. of temporalis muscle
- masseteric n. - sensory and motor inn. of the masseter muscle
- med/lat pterygoid nn. - sensory and motor inn. to medial and lateral pterygoid muscles
- inferior alveolar n.
- -> n. to mylohyoid: sensory and motor inn. to anterior digastric and mylohyoid muscles
What cranial nerve provides preganglionic parasympathetic connection to the auriculo-temporal nerve of CN V3?
CN IX axons arising form the otic ganglion
CN VI- abducens- target structures/function
motor innervation to the lateral rectus muscle
ACTION: ABDUCTION of the eye
CN VII- Facial n. - target structures
BRANCHIAL MOTOR
- n. to stapedius off of the main root–> needed to dampen sound
- (2ND pharyngeal arch- hyoid arch):
- –innervation of the posterior digastric ms and stylohyoid ms.
- –nn. to mm. of facial expression:
- temporal (frontalis and orbicularis oculi)
- zygomatic (zygomaticus major and levator labii superioris)
- buccal (buccinator, levator labii superioris, nasalis, orbicularis oris, depressor anguli oris, zygomaticus major)
- mandibular- depressor anguli oris, depressor labii inferioris, orbicularis oris
- cervical- (platysma)
SENSORY
–> main root of the facial nerve goes through stylomastoid foramen to become the posterior auricular n. –> innervation SKIN OF EAR
TASTE
- chorda tympani n. - taste innervation to ant. 2/3 of tongue (axons join the lingual nerve of V3 to innervate mucosa of the tongue)
- n. of the pterygoid canal axons travel with lesser palatine nerve of (CN V2) to innervate palate (TASTE)
PARASYMPATHETIC - “TASTE, SPIT”
—> preganglionic parasympathetic axons arising from the superior salivatory nucleus of the pons (making up facial n. then chorda tympani n.) synapse on the submandibular ganglion —> post para axons travel with lingual nerve (CN V3) to innervate sublingual and submandibular glands
- preganglionic para axons from the superior salivatory nucleus of the pons through the geniculate ganglion
- –> becomes greater petrosal nerve
- –> go through hiatus of greater petrosal n.
- –> become n. of pterygoid canal in pterygoid canal
- –> exit canal to synapse on pterygopalatine ganglion (anchored to CN V2)
- –> postganglionic para axons join zygomatic n. (V2) and lacrimal n. (V1) to innervate lacrimal gland
- –> postganglionic para axons travel with nasal nerves of V2 to innervate mucosa of nasal cavity, paranasal sinuses, nasopharynx, and roof of the oral cavity
What clinical disorder can occur due to inflammation at the stylomastoid foramen?
Bell’s Palsy –> hemiparesis at the face
- inflammation of structures going through stylomastoid foramen
- (main root of facial nerve)
** influences muscles of 2nd pharyngeal arch (facial expression, stylohyoid, posterior digastric)
What clinical disorder could occur if there was a lesion to the n. to the stapedius (coming off the main root of the facial nerve)?
unable to dampen sound
CN IX- glossopharyngeal- function
branchial motor
- -> becomes n. to stylopharyngeus after passing through sup/inf ganglion
- —–>inn. stylopharyngeus ms. (3rd pharyngeal arch) and superior pharyngeal constrictor (SWALLOWING AND SPEAKING)
sensory- visceral —> info from carotid body and sinus back to the medulla
- -> glossopharyngeal nerve branches into CAROTID BRANCH after going through superior ganglion
- ——-> CHEMORECEPTION: regulates concentration of o2/co2 at bifurcation between internal carotid a. and external carotid a.
- ——-> BARORECEPTION: regulates blood pressure at enlargement (right near bifurcation point)
sensory- touch/proprioception
– n. to stylopharyngeus: proprioception to stylopharyngeus
–pharyngeal branch: sensory inn. upper pharynx (gag reflex)
–tonsillar branch: sensory inn. of tonsillar mucosa
–lingual branch: sensory inn. (touch) of the post 1/3 of tongue
-tympanic nerve
—> sensory inn. to inner ear
—> lesser petrosal nerve (continuation of the tympanic n.) pre para axons come from inferior salivatory nuc. of medulla to innervate otic ganglion
—> post para axons travel with auricle-temporal nerve of
V3 to innervate Parotid gland (SPIT)
preganglionc/postganglionic parasympathetic
- -tympanic nerve into tympanic canaliculus
- -lesser petrosal nerve into hiatus for lesser petrosal and foramen vale
- -axons of lesser petrosal synapse at otic ganglion—> postganglionic fibers travel with auriculotemporal nerve (CN V3) to innervate parotid gland “SPIT
TASTE:
- lingual branch exits inferior ganglion and innervates POSTERIOR 1/3 tongue (mucosa and taste innervation)
