JCAHPO Ocular Anatomy & Physiology 3

Question 1

Which cranial nerve provides sensory innervation to the cornea and is responsible for triggering the blink (corneal) reflex?

Accepted Answer

Cranial nerve V (trigeminal)

Answer

Cranial nerve II (optic)

Answer

Cranial nerve III (oculomotor)

Answer

Cranial nerve VII (facial)

Question 2

The tear film is composed of three layers. Which layer, produced by goblet cells, is the innermost and provides adhesion to the corneal epithelium?

Accepted Answer

Mucin layer

Answer

Lipid layer

Answer

Aqueous layer

Answer

Meibomian layer

Question 3

The choroid is primarily responsible for which function?

Accepted Answer

Supplying oxygen and nutrients to the outer retina

Answer

Producing aqueous humor

Answer

Regulating pupil size

Answer

Draining vitreous

Question 4

Accommodation of the lens for near vision involves which action of the ciliary muscle?

Accepted Answer

Ciliary muscle contracts, zonules relax, lens becomes more convex

Answer

Ciliary muscle relaxes, zonules tighten, lens flattens

Answer

Ciliary muscle contracts, zonules tighten, lens elongates

Answer

Ciliary muscle relaxes, zonules relax, lens becomes more convex

Question 5

The cornea derives most of its oxygen supply from which source?

Accepted Answer

Atmospheric oxygen dissolved in tears

Answer

Central retinal artery

Answer

Anterior ciliary arteries

Answer

Aqueous humor only

Question 6

Which structure is responsible for draining aqueous humor from Schlemm's canal into the episcleral venous system?

Accepted Answer

Collector channels

Answer

Ciliary processes

Answer

Zonules of Zinn

Answer

Hyaloid canal

Question 7

The dilator pupillae muscle, which enlarges the pupil in dim light, is innervated by which nervous system pathway?

Accepted Answer

Sympathetic via the superior cervical ganglion

Answer

Parasympathetic via CN III

Answer

Somatic via CN VI

Answer

Parasympathetic via CN VII