Anatomy & Physiology of the Visual System Flashcards

Which extraocular muscle is responsible for primary abduction of the eye?

Answer: Lateral rectus

The lateral rectus, innervated by cranial nerve VI (abducens), is the primary abductor of the eye.

The visual pathway travels from the retina to the primary visual cortex located in which brain lobe?

Answer: Occipital lobe

The primary visual cortex (V1/striate cortex) is located in the occipital lobe, specifically in the calcarine fissure.

Which cranial nerve innervates the superior oblique muscle?

Answer: CN IV (Trochlear)

The trochlear nerve (CN IV) exclusively innervates the superior oblique muscle, making it the only cranial nerve to exit from the dorsal brainstem.

At the optic chiasm, which fibers decussate (cross) to the opposite side?

Answer: Nasal retinal fibers

Nasal retinal fibers, which carry temporal visual field information, cross at the optic chiasm, while temporal retinal fibers remain ipsilateral.

The fovea centralis contains predominantly which type of photoreceptors?

Answer: Cones only

The fovea centralis is packed exclusively with cone photoreceptors, providing maximum visual acuity and color discrimination in bright light.

The near reflex triad consists of accommodation, miosis, and which third component?

Answer: Convergence

The near reflex triad comprises accommodation (lens focusing), miosis (pupil constriction), and convergence (inward turning of both eyes) for near viewing.

Which layer of the retina contains the cell bodies of the photoreceptors?

Answer: Outer nuclear layer

The outer nuclear layer contains the nuclei (cell bodies) of both rod and cone photoreceptors.