Ocular Anatomy and Physiology Flashcards
7 cards from real AOA 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
Intraocular pressure (IOP) is primarily regulated by the balance between aqueous humor production and outflow through which primary drainage pathway?
Answer: Trabecular meshwork and Schlemm's canal
Approximately 80–90% of aqueous outflow occurs through the trabecular meshwork into Schlemm's canal, making this the conventional pathway primarily responsible for IOP regulation.
Which layer of the retina contains the cell bodies of the photoreceptors?
Answer: Outer nuclear layer
The outer nuclear layer contains the cell bodies (nuclei) of the rod and cone photoreceptors.
The ciliary muscle contraction during accommodation causes which change to the crystalline lens?
Answer: The lens becomes more convex as zonular tension decreases
When the ciliary muscle contracts, it moves anteriorly and inward, releasing zonular tension and allowing the elastic lens to assume a more spherical (convex) shape, increasing its power for near focus.
The macula lutea gets its yellow color from which pigments?
Answer: Lutein and zeaxanthin
The macular pigment is composed of lutein and zeaxanthin, two xanthophyll carotenoids that absorb blue light and are thought to protect the macula from phototoxic damage.
Which cranial nerve innervates the lateral rectus muscle?
Answer: CN VI (Abducens)
The abducens nerve (CN VI) exclusively innervates the lateral rectus muscle, which abducts the eye.
The retinal pigment epithelium (RPE) performs all of the following functions EXCEPT:
Answer: Production of aqueous humor
Aqueous humor is produced by the ciliary body epithelium, not the RPE; the RPE's roles include photoreceptor outer segment phagocytosis, vitamin A cycling, and forming the outer blood-retinal barrier.
The vitreous humor is composed primarily of which substance?
Answer: Hyaluronic acid and collagen fibrils
The vitreous is approximately 99% water, with the structural framework provided by a network of hyaluronic acid (providing viscosity) and collagen fibrils (type II and IX).