AOA Ocular Anatomy and Physiology 3

Question 1

The corneal endothelium maintains corneal deturgescence primarily through which mechanism?

Accepted Answer

Active ion pumping via Na+/K+-ATPase to move fluid from the stroma to the anterior chamber

Answer

Passive diffusion driven by oncotic pressure

Answer

Secretion of mucin to repel water

Answer

Contraction of tight junctions to prevent any fluid entry

Question 2

Horner's syndrome results from a lesion of which neural pathway?

Accepted Answer

Sympathetic pathway to the iris dilator and Müller's muscle

Answer

Parasympathetic pathway to the iris dilator

Answer

Parasympathetic pathway to the iris sphincter

Answer

Sympathetic pathway to the iris sphincter

Question 3

Which layer of the tear film, produced by the meibomian glands, serves as the outermost layer and prevents evaporation?

Accepted Answer

Lipid layer

Answer

Aqueous layer

Answer

Mucin layer

Answer

Glycocalyx layer

Question 4

The pupillary light reflex (direct and consensual) relies on which afferent pathway?

Accepted Answer

Optic nerve → pretectal nucleus → bilateral Edinger-Westphal nuclei

Answer

Optic nerve → lateral geniculate nucleus → visual cortex → Edinger-Westphal nucleus

Answer

Optic nerve → superior colliculus → ciliary ganglion

Answer

Optic nerve → lateral geniculate nucleus → ciliary ganglion

Question 5

Which of the following best describes the blood supply to the outer retina (photoreceptors and RPE)?

Accepted Answer

Choriocapillaris of the choroid

Answer

Central retinal artery capillaries

Answer

Posterior ciliary artery branches within the retina

Answer

Anterior ciliary arteries

Question 6

The physiologic blind spot corresponds to which retinal structure?

Accepted Answer

Optic nerve head (optic disc)

Answer

Fovea centralis

Answer

Ora serrata

Answer

Macula lutea

Question 7

Which structure forms the blood-aqueous barrier on the anterior surface of the iris?

Accepted Answer

Iris vascular endothelium with tight junctions

Answer

Iris pigment epithelium

Answer

Iris stroma endothelium

Answer

Non-pigmented ciliary epithelium