Ocular Anatomy and Physiology Flashcards
7 cards from real ABO NOCE Basic Opticianry practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Ocular Anatomy and Physiology flashcards as text
The retinal pigment epithelium (RPE) is located between which two structures?
Answer: Photoreceptors and choroid
The RPE is a single layer of pigmented cells located between the photoreceptor outer segments and the choroidal vasculature (Bruch's membrane).
Which structure is responsible for draining aqueous humor from the eye?
Answer: Schlemm's canal
Schlemm's canal (the scleral venous sinus) collects aqueous humor from the trabecular meshwork and drains it into the episcleral veins.
What percentage of the eye's total refractive power is provided by the cornea?
Answer: 67%
The cornea provides approximately two-thirds (about 43 of the total ~60 diopters, or ~67%) of the eye's total refractive power.
Which extraocular muscle is innervated by cranial nerve IV (trochlear nerve)?
Answer: Superior oblique
The trochlear nerve (CN IV) innervates only the superior oblique muscle, which depresses and intorts the eye.
The angle of the anterior chamber is formed by the junction of the:
Answer: Iris and cornea
The iridocorneal angle (anterior chamber angle) is formed where the peripheral iris meets the posterior cornea, and it contains the trabecular meshwork.
Which type of collagen is the primary structural component of the corneal stroma?
Answer: Type I collagen
Type I collagen is the predominant collagen type in the corneal stroma, arranged in regularly spaced lamellae to maintain corneal transparency.
Accommodation is the ability of the eye to change focus. Which structure changes shape during accommodation?
Answer: Crystalline lens
The crystalline lens changes its curvature (becomes more convex) during accommodation to increase the eye's refractive power for near vision.