Neuro cranial nerves Flashcards
Olfactory nerve function
olfaction
optic n function
vision
oculomotor nerve innervates…? what is their function
medial rectus, inferior rectus, superior rectus, inferior oblique > MOST EYE MOVEMENTS
palpebral muscles > HOLDS EYELIDS OPEN
ciliary muscles > PUPIL CONSTRICTION and ACCOMODATION
trochlear nerve innervates…? what is function
S4: superor obllique - down and out eye movement
trigeminal nerve innervates…? what is function
Sensation to face + corneal reflex
sensation anterior 2/3 of tongue
muscles of mastication
abducens nerve innervates…? what is function
L6: lateral rectus
OUT eye movement
facial nerve innervates…? what is function
facial muscles > facial movement
stapedius> controls acoustics of hearing (damage leads to HYPERACUSIS)
taste to anterior 2/3 of tongue
vestibulocochlear nerve innervates…? what is function
balance
hearng
glossopharyngeal nerve innervates…? what is function
poost 1/3 of tongue (taste+ sensation)
AND gag reflex
vagus nerve innervates…? what is function
sensation and motor to pharynx and laynx
include swallowing and speech
accessory nerve innervates…? what is function
SCM, trapezius
hypoglossal nerve innervates…? what is function
tongue muscles > tongue movement
what dermatome are the nipples
T4
what dermatome is the umbilicus
T10
CNIII palsy presentation
DOWN and OUT fixed eye gaze
ptosis (unable to open eye)
fixed dilated pupil (if PNS fibres also affected)
causes of CN3 palsy
stroke (posterior cerebral artery)
MS
basal skull fracture
What are causes of ptosis
Unilateral:
- Horner’s
- CN3 palsy
Bilateral:
- Myasthenia gravis
- Myotonic dystrophy
- congenital absence of muscles
Either: infection, inflammation, tumour
What is Horner’s syndrome, and what general pathophysiology is it caused by
CAUSED BY DAMAGE to SYMPATHETIC TRYNK
TRIAD OF:
- miosis (constricted pupil)
- ptosis
- facial anhydrosis
what can cause Horner’s syndrome
Vascular (carotid dissection, brainstem stroke)
Infection (pneumonia of lung apex)
Neoplasm (incl Pancoast tumour)
Idiopathic
Causes of Ptosis
nerve: (unilateral) CN3 palsy, Horner’s
NMJ: MG (bilateral)
muscle: myotonic dystrophy
How does pupil size vary between CN3 palsy and Horner’s
CN3: dilated
Horner’s: constricted