CPOA Ocular Anatomy 3 — Questions and Answers
Question 1: What is the primary function of the retinal pigment epithelium (RPE)?
- Producing vitreous humor
- Absorbing scattered light and supporting photoreceptors (Correct answer)
- Regulating aqueous outflow
- Providing corneal nutrition
Correct answer: Absorbing scattered light and supporting photoreceptors
The RPE absorbs excess light, recycles visual pigments, and provides metabolic support to the overlying photoreceptors.
Question 2: Which structure separates the anterior chamber from the posterior chamber of the eye?
- Lens
- Vitreous face
- Iris (Correct answer)
- Ciliary body
Correct answer: Iris
The iris acts as a diaphragm dividing the anterior and posterior chambers, with the pupil as the opening between them.
Question 3: The zonules of Zinn connect the lens to which structure?
- Choroid
- Retina
- Ciliary body (Correct answer)
- Sclera
Correct answer: Ciliary body
The zonular fibers (suspensory ligaments) extend from the ciliary body to the lens equator, holding the lens in position and transmitting ciliary muscle forces.
Question 4: Which layer of the retina contains the cell bodies of rod and cone photoreceptors?
- Inner nuclear layer
- Outer nuclear layer (Correct answer)
- Ganglion cell layer
- Inner plexiform layer
Correct answer: Outer nuclear layer
The outer nuclear layer contains the nuclei (cell bodies) of the rod and cone photoreceptors.
Question 5: What is the approximate horizontal diameter of a normal adult cornea?
- 7–8 mm
- 9–10 mm
- 11–12 mm (Correct answer)
- 13–14 mm
Correct answer: 11–12 mm
The average adult cornea measures approximately 11–12 mm horizontally and 10–11 mm vertically.
Question 6: The choroid is primarily composed of which type of tissue?
- Dense fibrous connective tissue
- Vascular tissue with melanocytes (Correct answer)
- Smooth muscle fibers
- Neural tissue
Correct answer: Vascular tissue with melanocytes
The choroid is a highly vascular layer containing blood vessels and melanocytes that nourish the outer retina and absorb stray light.
Question 7: Which extraocular muscle elevates and adducts the eye?
- Superior rectus (Correct answer)
- Inferior oblique
- Superior oblique
- Medial rectus
Correct answer: Superior rectus
The superior rectus primarily elevates the eye and has secondary actions of adduction and intorsion.
CPOA Ocular Anatomy 3
What is the primary function of the retinal pigment epithelium (RPE)?