Lecture 8 - Cranial nerves Flashcards
C I name + function
Olfactory nerve
Function: special sensory (or visceral afferent - smell)
C II name + function
Optic nerve
Function: special sensory (somatic afferent - vision)
Content of left optic tract
Medial fibers from right eye
+
Lateral fibers from left eye
Content of right optic tract
Medial fibers from left eye
+
Lateral fibers from right eye
In the optic nerve, ____ fibers cross-over but ____ stay on the same side
medial, lateral
C III name + function
Occulomotor (“eye mover”)
Function: mainly motor
C III - occulomotor innervates what? (5)
Superior, inferior and medial rectus muscles Inferior oblique muscle Levator palpabrae muscle Ciliary bodies (muscles) of the lens Iris
Where the nerve (CIII) divides into the superior and inferior divisions
Within the superior orbital fissure
C IV name + function + origin
Trochlear nerve
Function: mainly motor
Originates from the superiolateral aspect of the pons
T or F: The trochlear nerve passes through the inferior orbital fissure
FALSE, superior orbital fissure
Injury to CIV effect
Inhibits the eyeball from turning out and down (inferolaterally)
= Diplopoa
Only cranial nerve to emerge dorsally from the brainstem
CN IV - trochlear
C V name + function + location
Trigeminal nerve
Function: will be discussed for each division of CN V
Location: at the side of the pons
Largest cranial nerve
CV - trigeminal
The first two divisions of CN V are ____
purely sensory
Name the 3 divisions of the CN V
Ophthalmic division (C V1) Maxillary division (C V2) Mandibular division (C V3)
Ophthalmic (C V1) supplies ? (9)
Eyeball, conjunctiva, lacrimal sac and gland, nasal mucosa, frontal sinus, external nose, upper eyelid, forehead and scalp
C V1 passes where
Through the superior orbital fissure
C V2 passes where
Through the foramen rotundum
Maxillary division (C V2) relays sensation from?
From the skin of the face over the maxilla including the upper lip, maxillary teeth, nasal mucosa, maxillary sinuses and palate
The third division of the CN V is both a ____ and ____ nerve
Motor, sensory
C V3 passes where
Through the foramen ovale
Motor component of the CN V3
Muscles of mastication (Masseter, temporalis, medial & lateral pterygoid)
Sensory component of the CN V3
Skin over the mandible, lower lip and side of head, mandibular teeth, mucosa of the mouth and the posterior two thirds of the tongue
CN VI name + function + innervation
Abducens nerve
Function: mainly motor
Innervates the lateral rectus muscle
CN VI passes where
Through the superior orbital fissure
CN VII name + function
Facial nerve
Function: mixed, primarily a motor nerve, but also carries special sensory fibers (taste)
CN VII passes where
Emerges between the pons and medulla on the brain
Exits the skull through the internal acoustic meatus, facial canal, and STYLOMASTOID FORAMEN
Passes through the parotid gland
Facial nerves supplies (7 groups)
Muscles of facial expression
Taste to anterior two thirds of the tongue
Parasympathetic innervation to the submandibular, sublingual and lacrimal glands and mucous glands of the soft palate, nose and paranasal sinuses
CN VIII name + function + location
Vestibulocochlear nerve
Function: mixed (mainly sensory)
Located in the petrous portion of the temporal bone at the internal acoustic meatus
Nerve that DOES NOT exit the skull
Vestibulocochlear - CN VII
2 divisions of CN VIII
- Vestibular (equilibrium)
2. Cochlear (hearing)
CN IX name + function
Glossopharyngeal nerve
Function: mixed
Responsibility of CN IX
Conveying taste from the posterior one third of the tongue
CN IX supplies (7 things)
Sensory innervation to the pharyngeal mucosa, palatine tonsil, posterior one third of tongue, eustachian tube, middle ear, carotid sinus and carotid body
Only muscle innervated by CN IX
Stylopharygeus muscle
CN IX passes where
Through the jugular foramen to exit the skull
CN X name + function
Vagus nerve
Function: mixed
Responsibility of vagus nerve
Sensation from the inferior pharynx, larynx and thoracic & abdominal viscera
CN X innervates what
Muscles of the soft palate, pharynx, intrinsic laryngeal muscles and palatoglossus muscles of the tongue
Why is the vagus nerve called “the wanderer”
Due to its extensive innervation throughout the body
CN X exits where
Exits the skull at the medulla oblongata with CN IX at the jugular foramen
CN XI name + function + origin
Accessory nerve
Function: mainly motor
Originates from the medulla oblongata and spinal cord
Responsibility of CN XI (innervation)
Motor innervation of the sternocleidomastoid and trapezius muscles
CN XI exits where
Jugular foramen
CN XII name + function + origin
Hypoglossal nerve
Function: mainly motor
Originates from the medulla oblongata
CN XII exits where
Through the hypoglossal canal
CN XII supplies
All of the muscles of the tongue except palatoglossus (supplied by CN X)
What is the helpful mnemonic to remember the function of the cranial nerves
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