Cranial Nerves Flashcards
Most cranial nerves originate from the ________, except CN ______
Brainstem;
CN I: olfactory n
CN II: optic n
CN XI: spinal accessory n
Name the cranial nerves:
CN I: Olfactory CN II: Optic CN III: Oculomotor CN IV: Trochlear CN V: Trigeminal CN VI: Abducens CN VII: Facial CN VIII: Vestibulocochlear CN IX: Glossopharyngeal CN X: Vagus CN XI: Accessory CN XII Hypoglossal
Which of the following nerves have both sensory and motor
CN V: Trigeminal N.
CN VII: Facial N.
CN IX: Glossopharyngeal N.
CN X: Vagus N.
CN I: Olfactory
Nerve function:
special sensory- smell
What cranial fossa is the Olfactory Nerve located?
Anterior Cranial Fossa
What nerve arise from receptors in the nasal cavity
Olfactory Nerve
Location of olfactory nerve cell bodies:
olfactory epithelium
What is the anomisa deficit?
loss of smell
What nerve is located on the cribriform plate of the ethmoid bone?
Olfactory
CN II: Optic
Function:
Location of Cell Bodies and N:
Deficit:
Special Sensory: Vision
Location: Cell Body: retinal ganglia (not the brainstem); Nerve: superior to the midbrain
Deficit: Visual defects
What cranial fossa is the optic nerve located in?
Middle cranial nerve
Extraocular muscles attach to the ______
sclera
Movement of superior rectus:
Elevation: Up and In
Movement of the inferior rectus:
depression: down and in
movement of the medial rectus:
adduction (to the midline)
movement of the inferior oblique
Elevation: Up and Out
movement of the lateral rectus:
abduction
Movement of the superior oblique:
Depression: down and out
What is LR6 SO4 AO3?
Lateral rectus CN VI: Abducens
Superior occipital CN IV: Trochlear
All other muscles CN III: Oculomotor
Muscles & Functions of CNIII: Oculomotor
Eye muscles (4 extraocular + levator palpebrae superioris)
Spincher Pupillae Muscle: pupil constriction (parasympathetic)
Ciliary Muscle: lens accommodation for near vision (focus) (parasympathetic)
CN III: Oculomotor:
-Location of nerve cell bodies and nerve
Midbrain
Between midbrain and pons
Deficit of Oculomotor N.
Ptosis (superior eyelid drooping) Lateral Strabismus (eye down and out)
Ptosis (superior eyelid drooping) is caused by paralysis of ______ muscle
levator palpebrae superioris
The CN III: Oculomotor N. exits what foramen?
superior orbital fissure
Which is the following CNs is the only CN that exits from the posterior (dorsal) surface of the brainstem?
CN IV: Trochlear nerve
CN IV: Trochlear N
- Function:
- Location of Nerve Bodies & Nerve
- Deficit
Motor
posterior midbrain
laterally between the cerebrum and the pons
Superior oblique (SO) weakness or paralysis,
-Diplopia (double vision) when looking down
What sinus does the CN IV: Trochlear N. travel through?
Cavernous sinus
What foramina does the CN IV: Trochlear N. travel through?
superior orbital fissure
CN V: Trigeminal N. (B S&M)
-Function
Skin sensation, maxilla, mandible
Sensation for the face, dura, mucosa of the eye, orbital contents, sinuses, nasal cavities, nasopharynx, oral cavity, teeth, and general sensation for the anterior 2/3 of the tongue (V3- mandibular), part of the external ear, and external acoustic meatus
Muscle of Mastication:
- Temporalis
- Masseter
- Medial Pterygoid
- Lateral Pterygoid
Medial Pterygoid helps______ the mouth
open
What are the sensory function nerves of CN V: Trigeminal
-3 divisions
V1: ophthalmic nerve (S) -sensory innervation for cornea
V2: maxillary nerve (S)
V3: mandibular nerve (S&M)
CN V: Trigeminal N:
- Location of Nerve Cell Bodies
- Find it:
- Deficits
- Trigeminal ganglion (sensory) & pons
- on the lateral part of pons
- Weakened or paralysis of the muscle of mastication (masseter and temporalis)
- loss of sensation
- loss of corneal reflex (sensation)
V1 (ophthalmic) and V2 (maxillary) travel through what sinus?
Cavernous Sinus
V1: Opthalamic travels through what foramina
superior orbital fissure
V2: Maxillary travels through what foramina?
Foramen of rotumdum
V3: Mandibular travels through what foramina?
foramen of ovale
CN VI: Abducens/Abducent
- Function
- Location of Nerve Cell Bodies:
- Find it:
- Deficits:
- Eye muscle- Abducts Lateral Rectus (LR6)
- Pons
3 Between pons and medulla
- loss of ability to move eye laterally; medial strabismus(one eye cannot focus w/the other
Which CN pierces the dura covering the clivus and then enters the orbit via a superior orbital fissure?
CN VI: Abducens N.
CN VII: Facial N. (B: S&M)
1. Function:
- Muscle of facial expression (+3 other muscles)
- Taste sensation for anterior 2/3 of tongue
- Salvia production of sublingual and submandibular glands (parasympathetic
- Tear production from lacrimal gland (parasympathetic)
- Mucosa glands of nasal cavity, maxillary sinus, and palate (parasympathetic)
CN VII: Facial N
- Location
- Find it:
4: Deficits:
- Pons (motor), Geniculate ganglion (sensory)
- Lateral to CN VI: (abducens) between the pons and medulla
- Loss of corneal reflex (unable to blink)
- weekend or loss of facial movements
- loss of taste from anterior 2/3 tongue and soft palate
What foramina does CN VII: Facial N pass through?
Internal acoustic meatus
CN VIII: Vestibulocochlear
- Function:
- Location of Nerve Cell Bodies:
- FInd it:
4: Deficits:
- Special sensory: hearing and balance
- Vestibular ganglion/ spiral ganglion
- Lateral to CN VII (Facial N.) at the junction of the pons and medulla
- Tinnitus (ringing and buzzing of the ears)
- Vertigo( dizziness, loss of balance)
- impaired or loss of hearing
What foramina does the CN VIII: Vestibulocochlear N. travel though
Internal Acoustic Meatus
CN IX: Glossopharyngeal N. (B S&M)
1. Function:
- Swallowing (stylopharyngeus) -motor
- Taste and general sensation for posterior 1/3 of tongue
- Sensory from palatine tonsils, oropharynx, middle ear pharyngotympanic tube, mastoid air cells, carotid body, and sinus
- Salvia production of the parotid gland (parasympathetic)
CN IX: Glossopharyngeal N. (B S&M)
- Location of Nerve Cell Bodies
- Find it:
- Deficits
- Medulla (motor); Sensory ganglion (sensory)
- Lateral to the medulla
- Loss of taste and general sensation on posterior 1/3 of tongue
- changes in swallowing
- absent gag reflex (ipsilateral)
- palate deviation (contralateral)
What foramen does CN IX: Glossopharyngeal N. passes through?
jugular foramen
CN X: Vagus N. (B S&M)
1. Function
- Swallowing, Speech
- S & M to smooth muscles of the thorax and abdomen
- Provides branches to the following plexus:
- cardiac
- pulmonary
- esophageal
- viscera and foregut
Parasympathetic fibers
Sensory to Larynx and Laryngopharynx
Taste from epiglottis and pharynx
What CN gives motor function to all of the larynx
-motor of most the muscles of the: pharynx and soft palate
CN X: Vagus N.
Vagus: means wandering
CN X: Vagus N
- Location of Nerve Cell Bodies
- Find it:
- Deficits:
- Motor (medulla and nucleus ambiguus in medulla)
- Sensory (superior and inferior ganglion) - arises as a group of rootless form the lateral surface of the medulla
- Dysphagia: difficulty swallowing
- anesthesia to larynx (weak voice, hoarseness)
- Dysphonia: (difficulty speaking)
- Aphonia: (loss of voice)
- Inspiratory stridor (high pitched inspiratory sound)
- Heart rate abnormalities
What foramen does CN X: Vagus N pass through?
jugular foramen
CN XI: Accessory N (M)
1. Function:
Sternocleidomastoid (SCM) (Head RT, Cervical FLX)
Trapezius (shoulder shrug)
CN XI: Accessory N.
- Location of Nerve Cell Bodies
- Find it:
- Deficits
- arises as a series of rootless from the uopper 5-6 segments of the cervical spinal cord
- ascending through foramen magnum; lateral to the medalla
- Atrophy of trapezius and weakened shrugging
- Impaired rotary movements of the neck and chin to the opposite side due to SCM weakness
What foramina’s does CN XI: Accessory N pass through?
Enters: Foramen magnum
Exits: Jugular foramen
CN XII: Hypoglossal N. (M) 1. Function: 2. Location of Nerve Cell Bodies 3. Find it: 4 Deficits:
- Major tongue muscle
- arises a series of rootless from the ant. medulla
- anterolateral medulla
- when protruded the apex of the tongues deviates toward damaged nerve (ipsilateral side)
What is the passageway of CN XII: Hypoglossal N?
hypoglossal canal
- What cranial nerve provides taste (posterior 1/3 pharyngeal)?
- What cranial nerves provide general sensation (posterior 1/3 pharyngeal)?
CN IX: Glossopharyngeal N.
CN X: Vagus N.
- What cranial nerve provides taste? (2/3 anterior oral)
2. What cranial nerve provides a general sensation (2/3 anterior oral)
- CN VII: Facial N.
2. CN V: Trigeminal N. (V3- mandibular)
