exam 5 Flashcards
Name the 12 cranial nerves
I OLFACTORY II OPTIC III OCULOMOTOR IV TROCHLEAR V TRIGEMINAL VI ABDUCENS VII FACIAL VIII VESTIBULOCOCHLEAR IX GLOSSOPHARYNGEAL X VAGUS XI SPINAL ACCESSORY XII HYPOGLOSSAL
12 cranial nerves summary
I Olfactory: smell–>sensory
II Optic: vision: eyelid and eyeballs=sensory
III Oculomotor: eyeball=motor
IV Trochlear: eyeball (up and down)=motor
V Trigeminal:mastication and sensation to the mouth=both
VI Abducens: eye balls(running vision)= motor
VII Facial:facial movements, taste, salivary glands=both
VIII Vestibulocochlear: hearing and balance=sensory
IX Glossopharyngeal: taste, velar movements and taste = both
X Vagus: laryngeal movement, laryngeal sensation, heart and stomach= both
XI A spinal: neck movements= motor
XII Hypoglossal: tongue movement=motor
which cranial nerves have sensory FUNCTIONS?
I Olfactory: smell
II Optical: vision
VIII Auditory (vestibulocochlear): hearing and balance
Which cranial nerves have motor functions?
III Oculomotor: eyelid and eyeball movement IV Trochlear: eyeball movement VI Abducens: eyeball movement XI (Spinal) accessory: neck muscle XII Hypoglossal : tongue movement
Which cranial nerves have both sensory and motor functions?
V Trigeminal: mastication and sensation to the face
VII Facial: facial movements, taste, salivary glands
IX Glossopharyngeal: velar movements, taste
X Vagus: laryngeal movements, laryngeal sensation, heart & stomach
Explain the term afferent nerve
afferent=sensory=up ( ARRIVE) ASCENDING SIGNALS
- Information from periphery to brain ex: smell, pain
- neurons located outside of the CNS
Explain the term efferent nerve
motor= down and out (EXECUTE) DESCENDING SIGNALS
- information from the upper motor neurons to the brainstem (lower motor neurons) to the oro-facial muscles.
- located in the brainstem. .
define the term cranial nerve
- part of the peripheral nervous system
- provide the head & neck musculature with motor commands, & send sensory information from the head and neck to the brain.
clinical notes of cranial nerve V trigeminal
lesion of:
- main pontine sensory nucleus=IPSILATAREL
- spinal nucleus & peripheral nerve=TRIMINAL NEURALGIA (pain, demyelination)
- UMN=minimal bilateral weakness & chewing. JAW JERK REFLEX
- LMN=jaw DEVIATION on legion side=ATROPHY
clinical notes of cranial nerve VII facial
lesions of:
-UMN & corticobulbar tract= CONTRALATERAL PARALYSIS OF LOWER FACE ONLY
-LMN & peripheral nerve : IPSILATERAL PARALYSIS OF THE WHOLE SIDE OF THE FACE
-Any compression of VII=BELL’S PALSY:
LMN & nucleus salivatory;ONE SIDE PARLAYSED UP+DOWN; Hyperacusis (no stapedius reflex absent); Dry eye (parasymathical)
-Sensory nucleus: TASTE FUNCTION
-cortical nucleus: MINIMAL ON TASTE coz of bilateral prejection
clinical notes of cranial nerve XII hypoglossal
lesions of:
LMN & peripheral= TONGUE DEVIATION ON SAME SIDE OF LESION ; FLACCID PARALYSIS of the tongue; FASCICULATION; ATROPHY ON WEAK SIDE
-UMN & corticobulbar: TONGUE DEVIATION ON OPPOSITE SIDE OF THE LESION
What is the function of the I Olfactory nerve?
SMELL-sensory
tract of axons which terminates in the cortex
What is the function of the II Optical nerve?
Vision-sensory
optical tract from the retina to the optic chiasm
What is the function of the III Oculomotor nerve?
Motor; UNILATERAL INERVATION of eye lielid movement, PUPIL CONTRICTION, superior colliculus
What is the function of the IV Trochlear nerve?
Motor:UNILATERAL INNERVATION of Eyeball UP & DOWN.
-downward/lateral eyeball movement.
inferior colliculus
What is the function of the V Trigemal nerve?
Sensory and motor= MASTICATION & SENSATION TO THE FACE.
OPTHALMIC: forehead, eyes, nose (sens)
MAXILLAR: upper lip/teeth, cheeks & palate
MANDIBULAR: tongue, mandible, lower lip/teeth, cheeks, parts of ext. ear
MOTOR FUNCTION: UMN BILATERAL INNERVATION from the cortex to the LMN 50-50 (masseter,temporalis, external/internal pterygoid, anterior belly of digastric, tensor veli palatini, tensor tympani)
What is the function of the VI Abducens nerve?
Unilateral innervation of the muscles that move the eyeball laterally (side to side)
What is the function of the VII facial nerve?
FACIAL, SALIVARY GLAND
3 nuclei in brainstem
-Motor: innervates all facial muscles Parasympathetic :innervates glands of eyes and under tongue
-Sensory nucleus taste of 1st 2/3rd of tongue
Innervates: bilateral inn. of upper face muscles
unilateral/contralateral motor inn. of lower face (Only contralateral)
What is the function of the VIII vestibulocochlear nerve?
HEARING AND BALANCE-sensory
oThe spiral ganglion contains the bipolar cells that innervate the cochlea
oThe Scarpa’s ganglion containing the bipolar cells that innervate the labyrinth.
What is the function of the IX Glossopharyngeal nerve?
VELAR MOVEMENTS/TASTE: motor-sensory nuclei in the brainstem -sensory:2nd&3rd of tongue, afferent part of gag reflex parasympatic: parotid gland motor: stylopharyngeus
What is the function of the X vagus nerve?
motor: bilateral, pharyngeal, laryngeal
parasympathetic: heart, stomach, digestive tract
sensory: pharynx, meninges
What is the function of the XI accessory Spinal nerve?
neck muscles: Head turn and tilt, sternum and clavicle raise (sternocleidomastoid)
shrugging the shoulders (trapezius)
What is the function of the XII Hypoglossal nerve?
TONGUE MOVEMENTS-SENSORY
- INTRINSIC muscles: SHORTENING, concaving,NARROWING, elongating and flattening
- EXTRINSIC muscles: tongue OUT (genioglossus), UPWARD & BACKWARD drawing (styloglossus) & RETRACTION and depression (hyoglossus)
Define Bilateral innervation
muscles innervated by cranial nerves that receive fibers from both cerebral hemispheres 50-50
