Cranial Nerves Flashcards
CN XII
Hypoglossal
Motor to intrinsic and extrinsic muscles of the tongue
(note that if damaged tongue will point to side of lesion)
CN II
Optic
Special sense of vision
Contralateral
CN VII
Facial
Special sense of taste from the anterior 2/3 of tongue
Motor to muscles of facial expression
Parasympathetic to lacrimal, submandibular, and sublingual salivary glands
Branches of CN V
V = Trigeminal
V1 = Opthalmic division
V2= Maxillary division
V3 = Mandibular division
CN VI
Abductens
Motor to lateral rectus muscle of the eye
CN X
Vagus
Sensory to external ear, larynx, and esophagus
Motor to the muscles of the pharynx, larynx, palate, and esophagus (speech and swallowing, efferent limb of gag reflex)
Parasympathetic to thoracic and abdominal organs
Where does facial nerve exit the cranial cavitiy?
internal acoustic meatus
CN III
Oculomotor
Motor to the most extraocular musles of the eye
Parasympathetic to the pupillary sphincter and ciliary muscles of the eye
CN IV
Trochlear
Motor to superior oblique muslce of the eye
CN I
Olfactory
Special sense of smell
Nerves that exit cranial cavity through
Hypoglossal canal
Hypoglossal n (CN XII)
V1
Opthalmic division
Sensory to scalp, forehead, and nose, cornea and conjunctiva of the eye
Nerves that exit cranial cavity through
Cribiform plate
Olfactory n (CN I)
Motor functions of facial nerve
- As it passes through facial canal in temporal bone –> gives off motor branch to stapedius muscle in the ear (important in dampening sound recieved by tympanic membrane)
- As it exits stylomastoid foramen –> supplies facial expression muscles (temporal, zygomatic, buccal, marginal mandibular and cervical)
Sensory functions of Facial Nerve
- Chorda tympani –> taste from anterior 2/3 of tongue
- Cell body of chorda tympani nerve is within the facial ganglion
- Axons of this nerve run with lingual branch of V3 and eventually a seperate individual nerve
Which nerves transmit parasympathetic information
III
VII
IX
X
(mneumonic 1793)
Mandibular division (V3) Sensory branches
Exits at foramen ovale
Buccal nerve –> sensory information from inside of mouth and cheek
Ariculotemporal nerve –> carries sensory information from skin around external ear (also carries postganglionic parasympathetic fibers that innervate parotid gland)
Lingual nerve –> carries sensory innervation from anterior 2/3 of tongue
Inferior alveolar nerve –> runs with the mandible and carries sensory innervation from lower teeth –> exits mandible via mental foramen to become mental nerve –> carries sensation from a region of the lower lip and face
Where does facial nerve exit the skull?
Stylomastoid foramen at the base of the skull
Ophthalmic Division Sensory Branches
- Frontal Nerve–> runs in the superior aspect of the orbit and gives off a branch to the lacrimal gland. Exits the orbit and becomes the supraorbital nerve to provide sensation to part of face
- Other small branches provide sensory innervation of the cornea and conjunctiva of the eye
V2
Maxillary divisions
Sensory to cheeks, lower eye lid, nasal mucosa, upper lip, upper teeth and palate
The first 2 nerves (olfactory and optic) arise from
cerebrum
Where does facial nerve travel through?
Facial canal in the petrous portion of the temporal bone
CN IX
Gloddopharyngeal
Sensory to posterior 1/3 of tongue, palate, and oropharynx (afferent limb of gag reflex)
Motor to pharynx (swallowing)
Special sense of taste from posterior 1/3 of tongue
Parasympathetic to parotid salvary glands
V3
Mandibular division
Sensory to anterior 2/3 of tongue, chin, and lowe teeth.
Motor to the muscles of mastication
CN XI
Spinal accessory
Motor to sternocleidomastoud and trapexius muscles
Nerves that exit cranial cavity through
Superior oribital fissure
Oculomotor n (CN III)
Trochlear n (CN IV)
Opthalmic n (CNV1)
Abductens n (CN VI)
How is trigeminial nerve associated with parasympathetic functions in the head?
Conveys parasympathetic axons from other nerves (CNVII and CNIX) to their target organs
CNs III-XII emerge from
brain stem
Divisions of Trigmeninial Nerve
Ophthalmic (VI)–> exits cranium via superior orbital fissure
Maxillary (V2) –> exits cranial cavity via foramen rotundum
Mandibular (V3)–> exits cranial cavity via foramen ovale
Autonomic Functions of the Glossopharyngeal Nerve
- Preganglionic parasympathetic fibers from glossopharyngeal nerve synapse in otic ganglion behind mandible
- Postganglionic parasympathetic fibers join the ariculotemporal nerve to innervate the parotid salivary gland
Maxillary Division Sensory Branches
- Infraorbital nerve–> passes through infraorbital foramen –> provides sensory innervation to a part of the face
- Superior alveolar nerve –> sensation to upper teeth as well as some of the sinuses in the head and nasal mucosa
Nerves that exit cranial cavity through
foramen rotundem
Maxillary n (CN V2)
Branches of Mandibular Division of Trigeminial Nerve Function
Supply motor innervation to muscles of mastication (temporalis, masseter, medial and lateral pterygoid)
Autonomic Functions of the Facial Nerve
- Parasympathetic innervation of the lacrimal gland and submandibular and sublingual salivary glands
- in proximal portion of facial canal –> gives off greater petrosal nerve branch–> carries preganglionic parasympatheric fibers to the pterygopalatine ganglion. the postganglionic fivers from the ganglion joing the lacrimal nerve to innervate lacrimal gland
- Chorda tympani branch runs with lingual nerve –> carries preganglionic parasympathetic fibers to submandibular ganglion. Postganglionic fibers exit the ganglion and pass directly to submandibular and sublingual glands to stimulate salivation
Nerves that exit cranial cavity through
Optic canal
Optic n (CN II)
CN VIII
Vastibulocochlear
Special sense of hearing and balance
Nerves that exit cranial cavity through
Internal acoustic (auditory) meatus
Facial n (CN VII)
Vestibulocochlear n (CNVIII)
Nerves that exit cranial cavity through
foramen ovale
Mandibular n (CN V3)
Nerves that exit cranial cavity through
Jugular foramen
Glossopharyngeal n (CNIX)
Vagus n (CNX)
Accessory n (CN XI)
