The Pupillary Light Reflex | Structure & Clinical Interpretation

The video tutorial explains the pupillary light reflex (PLR), involving cranial nerves II (optic) and III (oculomotor). It covers the direct and consensual reflexes, demonstrating how light in one eye affects pupil constriction in the same or opposite eye. The tutorial includes a test demonstration and discusses diagnosing lesions in the reflex pathway, highlighting the effects of lesions on optic and oculomotor nerves.

What are the two cranial nerves involved in the pupillary light reflex?

Define the direct reflex in the context of the pupillary light reflex.

What is the difference between a direct reflex and a consensual reflex?

How does a consensual reflex occur?

What is the significance of the consensual reflex being named according to the eye that constricts?

Explain the role of the oculomotor nerve in the pupillary light reflex.

What happens to the pupillary light reflex if the left optic nerve is lesioned?

What would be the expected outcome of shining a light in the right eye of a person with a left optic nerve lesion?

Describe the effects of a lesion in the left oculomotor nerve on the pupillary light reflex.

How can one differentiate between an optic nerve lesion and an oculomotor nerve lesion based on the pupillary light reflex?