Lecture 22 - Skull and Cranial Nerves II Flashcards
What is CN I?
Olfactory n.
What information does CN I carry?
Olfactory information back to piriform
What are the three parts of the olfactory n.?
Olfactory filaments - bulb - tract
Where do CN I nerves enter?
Anterior cranial fossa via cribriform plate
What are vomeronasal ducts?
Associated with the flehmen reaction, pheromone detection
What is CN II?
Optic nerve
What are the three parts to the optic nerve?
Optic nerve - chiasm - tract
What infomation does CN II carry?
Information from the retinal ganglion cells to the lateral geniculate nucleus of the thalamus
What is contained within the optic nerve?
Fibers from one eye
What is contained within the optic chiasm?
Fibers from nasal retina of each eye
What is contained within the optic tract?
Ipsilateral temporal retinal fibers and contralateral nasal retina fibers
What is CN III?
Oculomotor n.
What information is carried within CN III?
Provides motor innervation to several extrinsic muscles that move the eye
Parasympathetic innervation to two intrinsic muscles of the eye
What are the actual muscles in the eye that the oculomotor neuron innervates?
Ventral oblique
Ventral, medial, dorsal recti
Levator palpebrae superioris
What are the actual muscles in the eye that CN III provides PNS innervation?
Ciliary muscles
Pupillary sphincter
What do the PNS do to the eye?
Cause the lens to become rounder and the pupil diameter to decrease
What is CN IV?
Trochlear
What does the CN IV do?
Provide motor innervation to dorsal oblique muscle
What is CN V?
Trigeminal
What are the branches of CN V?
1 - opthalmic
2 - maxillary
3 - mandibular
What is the function of CN V?
Provide sensory innervation to the face
What does the CN V3 do specifically?
Motor innervation to the muscles of mastication and muscles in the ear, pharynx with tensor in the name
What do the CN V branches exit from?
Trigeminal ganglion
What is CN VI?
Abducent
What is the function of CN VI?
Provide motor innervation to lateral rectus and retractor bulbi of the eye
What is CN VII?
Facial n.
What is the SNS function of CN VII?
Motor innervation to muscles of facial expression
Taste to anterior 2/3 of the tongue
What provides general sensory to the anterior 2/3 of the tongue?
CN V3
What is the PNS function of CN VII?
Innervation to pterygopalatine ganglion
Nasal mucosa - mucus production
Lacrimal gland - tear production
What is CN VIII?
Vestibulocochlear n.
What is the function of CN VIII?
Vestibular apparatus - balance
Cochlea - hearing
Where does CN VIII enter?
Temporal bone with facial nerve at the internal acoustic meatus
What is CN IX?
Glossopharyngeal
What is the function of CN IX?
Motor innervation to stylopharyngeus
Parotid gland
Taste to posterior 1/3 of tongue
Sensation to post. 1/3 of tongue, oropharynx, middle ear, auditory tube, carotid sinus, and carotid body
What is CN X?
Vagus n.
What SNS functions does CN X have?
Motor to muscles of soft palate (except tensor veli palatini), palatoglossus, pharynx, and larynx
What PNS functions does CN X have?
Cardiac muscle, viscera to left colic fissure
Taste buds around epiglottis, external acoustic meatus, dura mater in dorsal cranial fossa
What is CN XI?
Accessory n.
What muscles does CN XI innervate?
Brachiocephalicus, omotransversarius, sternocephalicus, and trapezius
What is CN XII?
Hypoglossal n.
What is the function of CN XII?
Motor innervation to almost all of the intrinsic and extrinsic tongue muscles
