Cranial Nerves


Terms in this set (...)

Mneumonic-Name of nerve
Oh, Oh, Oh, to touch and feel very green vegtables at home
Mneumonic-Type of Nerve Motor or Sensory
Some say marry money but my brother says bad business marry money
Only cranial nerves to contain only sensory neurons?
Cranial nerve I (olfactory)
Cranial nerve II (optic)
One cranial nerve is so predominantly sensory that its motor function is frequently overlooked:
-Cranial nerve VIII (vestibulocochlear)
-Cranial nerves I, II, and VIII are thus called sensory nerves (even though CN VIII is not exclusively sensory)
-Name of Cranial Nerve#1?
-Are the olfactory bulb and tract part of CN I?
-Function of CN I?
-CN I-Olfactory (Entirely Sensory)
-How is CN#1 tested?
-What is loss of smell called?
-Olfaction is assessed by having patient state whether or not they can perceive a common non-offensive smell
such as soap, cloves, flavored Chapstick®, coffee, or vanilla
-Loss of the sense of smell is called anosmia
-Name of Cranial Nerve#1?
-Function of CN II?
-Optic (Entirely Sensory)
-Short Function: Vision
-How is CN II assessed?
-Assessment of peripheral vision is one test associated with cranial nerve II
-The optic nerve passes through the optic foramen between the superior and inferior portions of the lesser wing of the sphenoid bone.
-Name of CN III?
-Mainly Sensory/Motor?
-What does CN III control?
-What does CN III innervate?
-What is the function of CN III?
-Mainly motor
-Controls extrinsic eye muscles not innervated by IV and VI
-Innervates intrinsic eye muscles: ciliary muscle (on lens) sphincter pupillae (iris)
Innervates most extrinsic eye muscles
Parasympathetic innervation to intrinsic eye muscles.
Innervates levator palpebrae superioris (muscle of the upper eyelid)
-Short function: eye movement
How is Oculomotor function assessed?
This is the pupillary light response test
Both pupils should constrict when light is shined in only one eye
-Name of CN IV?
-Mainly Sensory/Motor?
-Size of CN IV?
-What does CN IV innervate?
-Where does CN IV arise from?
-What is the function of CN IV?
-Mainly motor
-Smallest of the cranial nerves
-Innervates superior oblique muscle of the eye
-Only cranial nerve to arise from the posterior aspect of the brain stem
-Short function: eye movement
-The trochlea (trochle = pulley) is a pulley like loop through which the tendon of the superior oblique muscle passes
-The superior oblique moves the eyeball inferiorly and laterally
How is the trochlear nerve assessed?
Following a moving object with the eyes assesses cranial nerves III, IV, and VI since all three innervate extrinsic muscles of the eye.
-Name of CN V?
-Size of CN V?
-Where does the trigeminal nerve arise from?
-What does CN V provide innervation to?
-What is the function of CN V?
Largest of the cranial nerves
Emerges from pons isolated from other cranial nerves
Provides sensory neurons to face, head, and anterior 2/3 tongue
Motor neurons control chewing movements
Short function: mastication, facial sensation
How many roots does the trigeminal nerve have?
The trigeminal has two roots:
smaller motor root supplying the muscles of mastication
Larger sensory root, which has three branches:
What are the three branches of the trigeminal nerve called?
Ophthalmic nerve (V1)
Maxillary nerve (V2)
Mandibular nerve (V3)
How is the trigeminal nerve motor function assessed?
An assessment of motor function is to have the patient bite down while feeling the masseter muscle, then to have the patient attempt to open their mouth against resistance applied by the examiner
How is the trigeminal nerve sensory function assessed?
-An assessment of sensory function is to have the patient close their eyes, then the examiner touches the face with different objects (light pin touch, handle end of reflex hammer, Q-tip) and the patient describes the type of sensation as sharp, dull, soft, etc., the degree of pressure, and where it is on the face
-Cranial nerve V is the dermatome for most of the skin of the face and scalp
-Name of CN VI?
-What does CN VI provide innervation to?
-What is another name for CN VI?
-What is the function of CN VI?
-Mainly motor
-Innervates lateral rectus muscle of the eye
-Nerve is also called the abducent
-Short function: eye movement
What movement does innervation of the lateral rectus provide?
The lateral rectus muscle moves the eye laterally
It causes abduction of the eye (movement away from the midline of the body), hence the name of the nerve that supplies it.
How is the abducens muscle assessed?
Following a moving object with the eyes assesses cranial nerves III, IV, and VI since all three innervate extrinsic muscles of the eye
-Name of CN VII?
-What does CN VII provide motor innervation to?
-What does CN VII provide sensory innervation to?
-What is function of CN VII?
-Motor axons innervate muscles of facial expression
-Sensory axons from taste buds in the anterior two-thirds of the tongue (the mobile tongue)
-Short function: facial expression, taste, salivation, lacrimation
How is the facial nerve function assessed?
Having the patient exercise the muscles of facial expression by smiling, frowning and puffing both cheeks, and noting any asymmetries, drooping, sagging or smoothing of normal facial creases is an assessment of motor function.
-Name of CN VIII?
-What was CN VIII nerve formerly known as?
-What does CN VIII provide sensory innervation to?
-What is function of CN VII?
-Mainly sensory
-Formerly known as the acoustic, or auditory nerve
-Vestibular branch carries impulses for equilibrium
-Cochlear branch carries impulses for hearing
-Short function: balance, hearing
How is the vestbulocochlear nerve function assessed?
The examiner rubs fingers together both alternately and simultaneously very near to, yet not touching, each ear as one assessment of hearing
-Name of CN IX?
-What does CN VIII provide sensory innervation to?
-What is function of CN VII?
-Sensory axons on the posterior one-third of the tongue for taste from taste buds, and for tactile sensation
-Short function: taste, salivation, innervation of pharynx
How is the glossopharyngeal nerve function assessed?
Having the patient open their mouth, protrude their tongue, and say "Ahh" while the examiner observes the soft palate, uvula, and pharynx, as well as listens to the voice for evidence of hoarseness, is an assessment of both cranial nerves IX and X.
-Name of CN X?
-What is unique about CN X?
-What is function of CN X?
-Vagus Nerve
-The longest cranial nerve
-Short function: swallowing, talking, cardiac, GI tract, respiration, taste
The vagus nerve is widely distributed in the head, neck, thorax, and abdomen.
What is the sensory function of the vagus nerve?
Sensory function in taste, touch, pain, temperature, and proprioception from the epiglottis and pharynx; monitoring of blood pressure, oxygen, and carbon dioxide
What is the motor function of the vagus nerve?
Somatic motor function in swallowing, coughing, and voice production
What is the autonomic motor function of the vagus nerve?
Autonomic motor function (parasympathetic) in smooth muscle contraction and relaxation of GI tract, slowing of the heart rate, and secretion of digestive fluids
-Name of CN XI?
-Where does CN XI originate?
-What is unique about CN XI?
-What is the motor function of CN XI?
-What is function of CN XI?
-Accessory Nerve
-Originates from both the brain stem and the spinal cord, so it is sometimes called the spinal accessory (only cranial nerve to have a spinal cord component)
-Impulses to voluntary muscles used in swallowing, and to trapezius and sternocleidomastoid
-Short function: pharynx & larynx muscles, neck & shoulder movement
How is accessory nerve XI assessed?
Shrugging of the shoulders by the trapezius muscle against resistance from the examiner, as well as turning the head to the side, again against resistance
-Name of CN XII?
-What does CN XII innervate?
-What is function of CN XI?
-Innervates tongue for movements in speech and swallowing
-Short function: tongue movement
How is accessory nerve XII assessed?
Protrusion and side-to-side movement of the tongue is an assessment of the hypoglossal nerve