Reflexes of the orbit

Question 1

How would you test the ipsilateral pupillary light reflex?

Answer 1

Use a penlight + ask patient to look at a distant target e.g. over your shoulder.
Shine the penlight in 1 eye + observe the pupillary constriction in the same eye.
Repeat in the 2nd eye.

Question 2

How would you test the consensual pupillary light reflex?

Answer 2

Use a penlight + ask the patient to look at a distant target, e.g. over your shoulder.
Shine the penlight in 1 eye + observe the pupillary constriction in the other eye.
Repeat in the 2nd eye.

Question 3

What is the afferent arm of the accommodation reflex?

Answer 3

Optic nerve (CNII) + optic radiation to occipital lobe via Lateral Geniculate Nucleus.

Question 4

What is the efferent arm of the accommodation reflex?

Answer 4

Oculomotor nerve (CNIII) + Edinger-Westphal nucleus to ciliary muscle, medial rectus + 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 + zygomatic branches of the facial nerve (CNVII) initiating the motor response.