CPOT Ocular Anatomy & Physiology Flashcards
6 cards from real CPOT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 CPOT Ocular Anatomy & Physiology flashcards as text
The tear film is composed of three layers. Which layer, produced by the meibomian glands, prevents evaporation?
Answer: Lipid layer
The outermost lipid layer of the tear film is secreted by the meibomian glands and prevents the aqueous layer from evaporating.
Presbyopia results from the loss of which of the following?
Answer: Crystalline lens flexibility
Presbyopia occurs when the crystalline lens gradually hardens with age, reducing its ability to change shape for accommodation.
The cornea receives its oxygen supply primarily from:
Answer: The atmosphere and tear film
Because the cornea is avascular, it obtains most of its oxygen directly from the atmosphere through the tear film, with a smaller contribution from the aqueous humor.
Which cranial nerve controls the majority of extraocular muscles, including the medial, superior, and inferior recti?
Answer: Cranial nerve III
Cranial nerve III (oculomotor) innervates the medial, superior, and inferior rectus muscles, the inferior oblique, and the levator palpebrae superioris.
The sclera makes up approximately what percentage of the outer coat of the eye?
Answer: 83%
The sclera forms about five-sixths (approximately 83%) of the outer fibrous tunic, while the cornea covers the remaining one-sixth anteriorly.
Cones are most densely packed at the:
Answer: Fovea centralis
The fovea centralis contains the highest density of cone photoreceptors and no rods, providing the sharpest color and detail vision.