COT Ocular Anatomy and Physiology 1 — Questions and Answers
Question 1: Which layer of the cornea is responsible for maintaining corneal deturgescence through its pump function?
- Bowman's layer
- Stroma
- Descemet's membrane
- Endothelium (Correct answer)
Correct answer: Endothelium
The corneal endothelium contains Na+/K+-ATPase pumps that actively remove fluid from the stroma to maintain corneal clarity.
Question 2: The fovea centralis, responsible for the sharpest central vision, is located in which retinal structure?
- Optic disc
- Macula lutea (Correct answer)
- Ora serrata
- Peripheral retina
Correct answer: Macula lutea
The fovea centralis is a small depression at the center of the macula lutea and contains the highest concentration of cone photoreceptors.
Question 3: Aqueous humor is produced by which structure of the eye?
- Choroid
- Iris
- Ciliary body (Correct answer)
- Trabecular meshwork
Correct answer: Ciliary body
The ciliary body epithelium secretes aqueous humor into the posterior chamber, where it flows through the pupil into the anterior chamber.
Question 4: Which cranial nerve innervates the lateral rectus muscle?
- CN III
- CN IV
- CN VI (Correct answer)
- CN VII
Correct answer: CN VI
Cranial nerve VI (abducens nerve) exclusively innervates the lateral rectus muscle, which abducts the eye.
Question 5: The optic nerve head (optic disc) is located approximately how many degrees nasal to the fovea?
- 5 degrees
- 10 degrees
- 15 degrees (Correct answer)
- 25 degrees
Correct answer: 15 degrees
The optic disc is located approximately 15 degrees nasal to the fovea, corresponding to the blind spot in the visual field.
Question 6: Which photoreceptor type is primarily responsible for color vision and functions best in photopic (bright light) conditions?
- Rods
- Cones (Correct answer)
- Retinal ganglion cells
- Bipolar cells
Correct answer: Cones
Cones are concentrated in the macula and fovea, are responsible for color discrimination, and function optimally under bright lighting conditions.
COT Ocular Anatomy and Physiology 1
Which layer of the cornea is responsible for maintaining corneal deturgescence through its pump function?