Question 1

Where in the eye is Descemet's membrane located?&#10;A) Beneath the dilator pupillae fibers of the iris&#10;B) Beneath the 'endothelium' of the cornea&#10;C) Beneath the outer epithelium of the cornea&#10;D) Between the inner and outer nuclear layers of the retina&#10;E) Surrounding the lens fibers of the lens

Accepted Answer

Descemet's membrane is a layer of the cornea located beneath the 'endothelium'.

Question 2

Muller cells of the eye function to:&#10;A) Absorb stray intraocular light rays via intracellular accumulations of melanin&#10;B) Line the interior surface of the cornea&#10;C) Nourish and support neurons within the retina&#10;D) Phagocytize degraded membranous disks shed from rod cells&#10;E) Secrete aqueous humor

Accepted Answer

Muller cells are a type of glial cell found in the retina of the eye. They provide structural support and nutrition to the neurons within the retina. They also play a role in maintaining the normal ionic environment of the retina and removing excess neurotransmitters. While some other cells in the eye may perform the functions listed in the other answer choices, Muller cells specifically function to support and nourish the neurons within the retina.

Question 3

Meibomian glands are located adjacent to the:&#10;A) Epidermis of the eyelids&#10;B) Ciliary processes&#10;C) Extraocular muscles&#10;D) Nasolacrimal duct of the eye&#10;E) Ora serrata

Accepted Answer

Meibomian glands are located in the tarsal plates of the eyelids, adjacent to the epidermis of the eyelids, and are responsible for secreting meibum, an oily substance that prevents evaporation of the eye's tear film.

Question 4

What events occur during the process of accommodation?&#10;A) An increased tension on the suspensory ligament (zonular fibers)of the lens&#10;B) Dilation of the canal of Schlemm&#10;C) Flattening of the lens&#10;D) Focusing of light from close objects&#10;E) Relaxation of the ciliary muscle

Accepted Answer

Accommodation is the process by which the eye changes optical power to maintain a clear image (focus) on an object as its distance varies. This involves focusing light from close objects onto the retina, which is achieved by changing the shape of the lens.

Question 5

Variations in eye color are determined by the number of pigmented cells in the:&#10;A) Ciliary epithelium&#10;B) Corneal epithelium&#10;C) Corneal stroma&#10;D) Iris epithelium&#10;E) Iris stroma

Accepted Answer

Eye color variations are primarily determined by the amount and distribution of melanin in the iris stroma.

Question 6

An anatomically unusual cilium is found in which ocular structure?&#10;A) In connective tissue cells of the choroid&#10;B) In rod photoreceptor cells,at the junction of the inner segment with the outer segment&#10;C) On smooth muscle cells of the constrictor pupillae&#10;D) On the surface of epithelial cells of the ciliary processes&#10;E) Projecting from pigment epithelial cells of the retina

Accepted Answer

The anatomically unusual cilium is found in rod photoreceptor cells at the junction of the inner segment with the outer segment. It is called the "connecting cilium" and plays a crucial role in the transport of proteins and lipids between the two segments, which are specialized for different functions.

Question 7

Glaucoma is caused by:&#10;A) Blocked outflow from the anterior chamber into the trabecular meshwork&#10;B) Blocked outflow from the canal of Schlemm into the scleral veins&#10;C) Blocked outflow from the posterior chamber into the anterior chamber&#10;D) Blocked outflow from the trabecular meshwork into the canal of Schlemm&#10;E) Secretion of too much aqueous humor

Accepted Answer

Glaucoma is caused by blocked outflow from the trabecular meshwork into the canal of Schlemm. This blockage leads to increased intraocular pressure which can damage the optic nerve and result in vision loss.

Question 8

Aqueous humor is secreted by cells of the:&#10;A) Canal of Schlemm&#10;B) Ciliary processes&#10;C) Iris&#10;D) Pigment epithelium&#10;E) Trabecular meshwork

Accepted Answer

Aqueous humor is secreted by the ciliary processes, which are part of the ciliary body in the eye. The other structures listed are involved in the drainage or regulation of aqueous humor, but not in its secretion.

Question 9

The highest concentration of cone cells in the retina can be found in which region?&#10;A) Conjunctiva&#10;B) Fovea&#10;C) Limbus&#10;D) Optic disk&#10;E) Ora serrata

Accepted Answer

The fovea is the region of the retina that is responsible for high-acuity vision and contains the highest concentration of cone cells. Cone cells are responsible for color vision and high visual acuity. The other options do not contain a high concentration of cone cells.

Deck 19: Eye and Adnexa