Reflexes of the orbit

Question 1

How would you test the ipsilateral pupillary light reflex?

Answer 1

Use a penlight and ask the patient to look at a distant target, e.g. over your shoulder.
Shine the penlight in one eye and observe the pupillary constriction in the same eye. Repeat in the second eye.

Question 2

How would you test the consensual pupillary light reflex?

Answer 2

Use a penlight and ask the patient to look at a distant target, e.g. over your shoulder.
Shine the penlight in one eye and observe the pupillary constriction in the other eye. Repeat in the second eye.

Question 3

What is the afferent arm of the accommodation reflex?

Answer 3

Optic nerve (CNII) and optic radiation to occipital lobe via LGN.

Question 4

What is the efferent arm of the accommodation reflex?

Answer 4

Oculomotor nerve (CNIII) and Edinger-Westphal nucleus to ciliary muscle, medial rectus and sphincter pupillae muscle.

Question 5

What is the afferent arm of the corneal reflex?

Answer 5

Nasociliary branch of the ophthalmic division (V1) of the trigeminal nerve (CNV) sensing the stimulus on the cornea only.

Question 6

What is the efferent arm of the corneal reflex?

Answer 6

Temporal and zygomatic branches of the facial nerve (CNVII) initiating the motor response.