Week 7 - The Cranial Nerves Flashcards
What are the 12 cranial nerves?
- Olfactory
- Optic
- Oculomotor
- Trochlear
- Trigeminal
- Abducens
- Facial
- Vestibulocochlear
- Glossopharyngeal
- Vagus
- Accessory
- Hypoglossal
What is the function of CNI?
Olfactory - sense of smell
What is the function of CNII?
Optic - sense of sight
What is the function of CNIII?
Oculomotor - elevation of the upper eyelid and motor innervation of all the extraocular muscles except the superior oblique and lateral rectus muscles.
Innervates extraocular muscles:
- levator palpebrae superioris (elevation upper eyelid)
- inferior oblique (extorsion and elevation)
- superior rectus (elevation and intorsion)
- medial rectus (adduction)
- inferior rectus (intorsion and adduction)
Oculomotor - parasympathetic innervation via Edinger-Westphal nucleus in the Pupillary Light Reflex
What is the function of CNIV?
Trochlear - motor innervation of the superior oblique muscle - intorsion and depression of the eye
What is the function of CNVI?
Abducens - motor innervation of the lateral rectus muscle - abduction of the eye
What are the 3 main divisions of the trigeminal nerve?
V1 - ophthalmic
V2 - maxillary
V3 - mandibular
What is the function of CNV-1?
Ophthalmic - Trigeminal
Sensory innervation to the scalp and face above the lower eyelid
What is the function of CNV-2?
Maxillary - Trigeminal
Sensory innervation to the face between the lower eyelid and upper lip
What is the function of CNV-3?
Mandibular - Trigeminal
Sensory innervation to the face below the upper lip
Motor innervation to the muscles of mastication
What is the function of CNVII?
Facial - motor, parasympathetic and sensory
Motor - muscles of facial expression
Parasympathetic - salivary glands - submandibular and sublingual
Parasympathetic - lacrimal glands
Sensory Taste - anterior 2/3 of the tongue
Sensory General - small area around the concha of the auricle
What is the function of CNVIII?
Vestibulocochlear - sensory only
Vestibular organ - balance and detecting motion/position of the head
Cochlear organ - sense of hearing
What is the function of CNIX?
Glossopharyngeal - motor, parasympathetic and sensory
Motor - stylopharyngeus muscle of pharynx
Parasympathetic - parotid gland (salivary gland)
Sensory Taste - posterior 1/3 tongue
Sensory General - posterior 1/3 tongue, oropharynx, carotid body and sinus, middle ear and Eustachian tube.
Innervates the oropharynx, carotid body and sinus, posterior 1/3 of the tongue, middle ear cavity and Eustachian tube.
What is the function of CNX?
Vagus - motor, parasympathetic and sensory
Motor - majority of muscles of the larynx, pharynx and soft palate - i.e. speech and swallowing
Parasympathetic - smooth muscle of trachea, bronchi, GI tract and regulates heart rhythm (innervating cardiac smooth muscle)
Sensory - internal surfaces of laryngopharynx and larynx. visceral sensation to hollow viscera - heart, lungs, foregut and midgut (up to the distal-most part of the transverse colon).
What is the function of CNXI?
Accessory - motor only
innervates trapezius and sternocleidomastoid muscles in the neck that allow movement of both the head and neck
What is the function of CNXII?
Hypoglossal - motor only
innervates the intrinsic and extrinsic muscles of the tongue (except - palatoglossus)
allows movement of the tongue relative to itself
What foramina does each of the cranial nerves pass through?
olfactory - foramina of the cribiform plate optic - optic canal oculomotor - superior orbital fissure trochlear - superior orbital fissure trigeminal ophthalmic - superior orbital fissure trigeminal maxillary - foramen rotundum trigeminal mandibular - foramen ovale abducens - superior orbital fissure facial - internal acoustic meatus vestibulocochlear - internal acoustic meatus glossopharyngeal - jugular foramen vagus - jugular foramen accessory - jugular formaen hypoglossal - hypoglossal canal
What cranial nerve nuclei are associated with the oculomotor nerve?
oculomotor nucleus - midbrain - motor innervation of extraocular muscles and upper eyelid
Edinger-Westphal nucleus - midbrain - parasympathetic innervation through pupillary light reflex
What cranial nerve nuclei are associated with the trochlear nerve?
trochlear motor nucleus - midbrain - motor innervation of superior oblique extraocular muscle
What cranial nerve nuclei are associated with the abducens nerve?
abducens motor nucleus - pons - motor innervation of lateral rectus muscle
What cranial nerve nuclei are associated with the vestibulocochlear nerve?
vestibulocochlear nucleus - pons - divided into larger vestibular and smaller cochlear nuclei giving sense of balance, motion of head and hearing
What cranial nerve nuclei are associated with the accessory nerve?
accessory motor nucleus - medulla oblongata/cervical portion of spinal cord - motor innervation of trapezius and sternocleidomastoid muscles
What cranial nerve nuclei are associated with the hypoglossal nerve?
hypoglossal motor nucleus - medulla oblongata - motor innervation of intrinsic and extrinsic muscles of the tongue (except - palatoglossus)
What cranial nerve nuclei are associated with the trigeminal nerve?
Motor nucleus of trigeminal nerve - located in upper portion of pons, medial to sensory trigeminal nucleus - linked to mandibular division which innervates muscles of mastication
Sensory nucleus of trigeminal nerve - large and extends from the cerebral peduncles of the midbrain to the medulla and upper portion of the spinal cord - sensory innervation of the face
It has three parts - upper: mesencephalic nucleus / middle: principal nucleus / lower: spinal nucleus
spinal trigeminal sensory nucleus also associated with facial, glossopharyngeal and vagus cranial nerves.
What cranial nerve nuclei are associated with the facial nerve?
Facial Motor Nucleus - found in the pons, anterolateral to the abducens nerve - muscles of facial expression
Superior Salivary Nucleus - in the pons - parasympathetic innervation of lacrimal, sublingual and submandibular glands
Spinal Trigeminal Sensory Nucleus - extending from the pons into the medulla and upper portion of cervical spinal cord - general sensory innervation to area around the concha of the auricle
Nucleus of the Solitary Tract - special sensory innervation - taste anterior 2/3 tongue
What cranial nerve nuclei are associated with the glossopharyngeal nerve?
Nucleus Ambiguus - found in medulla, lying deep to the reticular formation - motor innervation to stylopharyngeus muscle of pharynx
Inferior Salivary Nucleus - in the pons below the superior salivary nucleus - parasympathetic innervation of parotid gland
Nucleus of the Solitary Tract - important role in reflex control of cardiovascular and respiratory functions
Nucleus of the Solitary Tract - special sensory innervation - taste posterior 1/3 tongue
Spinal Trigeminal Sensory Nucleus - general sensory innervation of posterior 1/3 tongue, oropharynx, carotid body and sinus, middle ear and Eustachian tube.
What cranial nerve nuclei are associated with the vagus nerve?
Nucleus Ambiguus - found in medulla, lying deep to the reticular formation - motor innervation to majority of muscles of the larynx, pharynx and soft palate
Dorsal Motor Vagus Nerve - parasympathetic innervation of smooth muscle of trachea, bronchi, GI tract and regulates heart rhythm (innervating cardiac smooth muscle)
Nucleus of the Solitary Tract - special sensory innervation - tongue (root/epiglottis portion) and visceral sensation to heart, lungs, foregut and midgut
Spinal Trigeminal Sensory Nucleus - general sensory innervation to posterior ear, external auditory meatus, and posterior and external surface of tympanic membrane
