cranial nerves 3,4,6

Question 1

what is the name of cranial nerves 3,4,6 and where do they supply

Answer 1

3 = occulomotor 
4 = trochlear 
6 = abducens 
motor nerves to extra ocular muscles of eyes - controlling movement of eyeball
- all somatic efferent nerves

Question 2

what do occulomotor nerves supply

Answer 2

• innervate 4 of 6 extra ocular muscles
• superior, inferior and medial rectus muscles
• inferior oblique muscles
• also control elevation of eyelid
• also constrictors and ciliary muscles

Question 3

what do trochlear nerves supply

Answer 3

• superior oblique muscles

Question 4

what do abducens nerves supply

Answer 4

• lateral rectus muscles

Question 5

what is the clinical test for all three muscles and what is the additional test for oculomotor nerve

Answer 5

• following end of pen and you move it across visual fields

- oculomotor nerve is to shine torch into eyes and check for pupillary light reflex

Question 6

damage to oculomotor nerve

Answer 6

• double vision [diplopia]
• lateral strabismus [squint]
• dilated pupil in affected eye

Question 7

damage to abducens

Answer 7

• diplopia

- medial strabismus

Question 8

damage to trochlea

Answer 8

• vertical diplopia [eye drifts up]

- patient inclines head to opposite side to fuse different images