COT Ocular Anatomy and Physiology 4

Question 1

Which layer of the cornea is responsible for approximately 90% of its thickness?

Accepted Answer

Stroma

Answer

The stroma constitutes about 90% of the corneal thickness and is composed of regularly arranged collagen lamellae.

Question 2

The canal of Schlemm is primarily involved in:

Accepted Answer

Aqueous humor outflow

Answer

The canal of Schlemm collects aqueous humor from the trabecular meshwork and drains it into the episcleral venous system.

Question 3

Which photoreceptors are most densely concentrated in the fovea centralis?

Accepted Answer

Cones

Answer

The fovea centralis contains only cones at its center, providing the highest visual acuity and color discrimination.

Question 4

The ciliary body performs which TWO primary functions?

Accepted Answer

Produces aqueous humor and controls accommodation

Answer

The ciliary body secretes aqueous humor via the ciliary epithelium and controls lens shape for accommodation through the ciliary muscle.

Question 5

The optic nerve head (optic disc) lacks photoreceptors, creating what clinical finding?

Accepted Answer

Physiologic blind spot

Answer

The optic disc has no photoreceptors, creating a natural blind spot approximately 15 degrees temporal to fixation.

COT - Certified Ophthalmic Technician Practice Test