Cranial Flashcards
What is the function of the I (Olfactory) nerve?
Smell
What is the primary function of the II (Optic) nerve?
Sight
List three functions of the III (Oculomotor) nerve.
- Eye movement (MR, IO, SR, IR)
- Pupil constriction
- Accommodation
- Eyelid opening
What is the function of the IV (Trochlear) nerve?
Eye movement (SO)
What are the two main functions of the V (Trigeminal) nerve?
- Facial sensation
- Mastication
What is the function of the VI (Abducens) nerve?
Eye movement (LR)
What are the functions of the VII (Facial) nerve?
- Facial movement
- Taste (anterior 2/3rds of tongue)
- Lacrimation
- Salivation
What are the functions of the VIII (Vestibulocochlear) nerve?
- Hearing
- Balance
What are the functions of the IX (Glossopharyngeal) nerve?
- Taste (posterior 1/3rd of tongue)
- Salivation
- Swallowing
- Mediates input from carotid body & sinus
What clinical signs result from a palsy of the III (Oculomotor) nerve?
- Ptosis
- ‘Down and out’ eye
- Dilated, fixed pupil
What clinical sign results from a palsy of the IV (Trochlear) nerve?
Defective downward gaze - vertical diplopia
What are the possible consequences of lesions in the V (Trigeminal) nerve?
- Trigeminal neuralgia
- Loss of corneal reflex (afferent)
- Loss of facial sensation
- Paralysis of mastication muscles
- Deviation of jaw to weak side
What clinical sign results from a palsy of the VI (Abducens) nerve?
Defective abduction → horizontal diplopia
What are the consequences of lesions in the VII (Facial) nerve?
- Flaccid paralysis of upper + lower face
- Loss of corneal reflex (efferent)
- Loss of taste
- Hyperacusis
What symptoms are associated with lesions of the VIII (Vestibulocochlear) nerve?
- Hearing loss
- Vertigo
- Nystagmus
What are the consequences of lesions in the IX (Glossopharyngeal) nerve?
- Hypersensitive carotid sinus reflex
- Loss of gag reflex (afferent)
What is the primary function of the X (Vagus) nerve?
- Phonation
- Swallowing
- Innervates viscera
What are the clinical signs associated with lesions of the X (Vagus) nerve?
- Uvula deviates away from site of lesion
- Loss of gag reflex (efferent)
What is the function of the XI (Accessory) nerve?
Head and shoulder movement
What are the clinical signs of lesions in the XI (Accessory) nerve?
Weakness turning head to contralateral side
What is the primary function of the XII (Hypoglossal) nerve?
Tongue movement
In which direction does the tongue deviate in case of a lesion of the XII (Hypoglossal) nerve?
Towards side of lesion
