Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
29 Cards in this Set
- Front
- Back
Only sensation that does not synapse in the thalamus before going to the cerebral cortex and deep brain structures |
Olfaction: terminates in underside of frontal cortex and some terminate in amyg and hypothalamus |
|
Foster–Kennedy syndrome |
a meningioma compresses the olfactory nerve and the nearby optic nerve. Damage to those two nerves causes the combination of unilateral blindness and anosmia. If the tumor grows into the frontal lobe, it can also produce personality |
|
Causes of anosmia
|
Head trauma can shear off the olf. nerves as they pass through the cribriform plate. Inhaling chromium, aluminum, iron. 90% of patients with parkinson, lewy bodies, Alz, etc. lose sense of smell |
|
Two functions of optic nerves |
vision, adjusting the size of pupil |
|
pupillary light reflex |
change in pupil size after exposure to light. small branches from optic nerve travel to midbrain (afferent) -> CNIII (efferent)->constricts pupil size. Lack of light reflex signals brain death |
|
How does MS cause optic neuritis when CNII is in the PNS? |
CNII myelin is derived from oligodendrocytes rather than schwann cells so it is an extension of the CNS. Thus, CNS diseases impact CNII. |
|
Function of CNIII, CNIV, CNVI |
maintains conjugate gaze; dysconjugate gaze is marked by diplopia |
|
Occulomotor impairment |
distinctive constellation: a dilated pupil, ptosis, and outward deviation (abduction) |
|
trochlear nerve damage |
Function: controls superior oblique muscle responsible for depression of the eye when adducted (turned inward). To compensate pts will tilt head away from affected side. |
|
abducens nerve function |
innervates its ipsilateral lateral rectus muscle, which abducts the eye. Damage leads to inward deviation (adduction) of the eye from the unopposed medial pull of the oculomotor |
|
strabismus |
congenital dysconjugate or “crossed” eyes, strabismus, does not cause double vision |
|
Trigeminal (fifth) nerve |
convey sensation from the face and innervate the large, powerful muscles that protrude and close the jaw. Because these muscles’ main function is to chew, neurologists often call them “muscles of mastication.” |
|
Ways to test the trigeminal nerve |
touch sides of face, test corneal reflex, jaw jerk reflex (closing jaw after tap) |
|
MLF syndrome (medial longitudinal fasciculus) syndrome |
heavily myelinated midline tract between pons and midbrain that links oculomotor and abducens nerves. Interruption causes nystagmus of abducting eye, failure of adducting eye to cross midline (common in MS) |
|
Injury to trigeminal nerve causes: |
hypoactive jaw jerk; corneal reflex impairment; deviation of jaw toward side of lesion, facial hypalgesia - common causes include gun shot wounds, tumor of nasopharyngeal area, acoustic neuromas; herpes infects trigeminal often causing trigeminal neuralgia (terrible pain) |
|
Facial Nerve does what? |
CNVII: both sensory and motor, conveys taste and innervates the facial muscles. (smile, frown, wink, raise eyebrows, etc.). |
|
CNVII Damage |
ipsilateral paresis of face (upper and lower). Note: injuries of CNS cause only lower facial paresis. loss of sensation from first 2/3rds of tongue. |
|
Bell's palsy |
sudden onset, idiopathic facial paralysis, usually with loss of taste sensation (due to infection of CNVII, lyme disease, lacerations, cerebellopontine tumors |
|
Acoustic Nerve functions |
CNVIII has two divisions: cochlear nerve transmits auditory impulses from middle and inner ear to superior temporal gyri. Vestibular nerve transmits info about equilibrium, orientation, and change of position aiding in balance. |
|
Most common form of hearing loss with aging? |
presbycusis: 25% of older adults, loss of high frequency sound and progresses to all frequencies. CNVIII cochlear mechanism withers as we age. Can be misdiagnoses as dementia due to sensory deprivation |
|
tinnitus |
ringing, buzzing, whistling in the ears. Aspirin can damage inner ear, ischemia, possible symptom of acoustic neuroma if unilateral. |
|
function of CNIX |
glossopharngeal brings taste sensation from posterior 2/3rds of tongue. Innervates (increases secretion of) parotid salivary gland. Motor: one pharyngeal muscle (stylopharyngeus) |
|
Vagus Nerve Sensory functions |
CNX visceral sensory information from pharynx, larynx, carotid bodies, heart, lungs, most abdominal organs. general sensory information from external auditory canal, eardrum, and pharynx |
|
Vagus Nerve Motor Functions |
most pharyngeal muscles, laryngeal muscles |
|
Bulbar Palsy |
damage to the "bulbar" nerves IX, X, XI causes dysarthria, dysphagia with hypoactive jaw and gag reflexes. Usually a brainstem lesion and can also be associated with damage to corticospinal tract (UMN signs like babinski reflex) |
|
Spinal Accessory functions |
Accessory nerve is a cranial nerve that controls certain neck muscles. It is coiled in appearance. It is divided into spinal and cranial parts, but its cranial part is often disregarded. The spinal accessory nerve provides the sternocleidomastoid and trapezius neck muscles with motor function. |
|
How to assess for bulbar palsy |
spontaneous speech will have a thick, nasal intonation or will be mute. Palatal and pharyngeal paresis will lead to absent jaw jerk reflex. Respiration may also be damaged and require "Iron lung" (guillann-barre, ALS, etc. can cause this) |
|
Pseudobulbar Palsy |
when frontal lobe damage rather than brainstem causes dysarthria and dysphagia. Also associated with sudden unprovoked episodes of laughter or emotional outbursts. Aphasia and dementia may occur. Speech has an explosive cadence. Will have hyperactive jaw jerk and face will sag due to corticobulbar tract damage. |
|
Hypoglossal |
CNXII innervates muscles of the tongue. Damage will cause tongue to deviate in direction of weak side (tongue points to the lesion). |