Ch. eye

Name the largest portion of the fibrous layer. A. Choroid B. Sclera C. Conjunctiva D. Cornea

B

How many extrinsic eye muscles are attached to the exterior surface of each eyeball? A. three B. four C. five D. six

D

Identify the neural layer. A. Sclera B. Retina C. Choroid D. Optic nerve

B; Correct. The retina is the neural layer that senses incoming visual information and sends that sensory input to the brain through the optic nerve.

Identify the parts of the fibrous layer. A. Cornea and lens B. Cornea and iris C. Sclera and conjunctiva D. Sclera and cornea

D;

The __________ is a clear, watery fluid that helps to maintain the intraocular pressure of the eye and provides nutrients for the avascular lens and cornea. A. aqueous humor B. vitreous humor

A

Identify the areas that are filled with aqueous humor. A. The anterior and posterior chambers B. The posterior chamber and the posterior segment C. The anterior and posterior segments D. The anterior chamber and the posterior segment

A; Correct. The anterior and posterior chambers make up the anterior segment, which is filled with aqueous humor.

Identify the structure that allows light to first enter the eye. A. Cornea B. Lens C. Sclera D. Pupil

A; Correct. The cornea is the transparent portion of the fibrous layer where light enters the eyeball into the anterior chamber before passing through the pupil to the lens.

Identify the structure that regulates the amount of light entering the posterior segment of the eye. A. Iris B. Cornea C. Lens D. Pupil

A; Correct. The iris is a muscular structure composed of both circular and radially arranged smooth muscle cells. It is capable of changing the shape of the pupil, thereby adjusting the amount of light passing through the lens.

Which of the following regions is known as the blind spot? A. Ciliary body B. Optic disc C. Fovea centralis D. Macula lutea

B; Correct. The optic disc is where the optic nerve exits the eye. Photoreceptor cells are not present in this region, and therefore visual information can not be received in this area.

Identify the muscular structure that anchors the lens in place. A. Iris B. Ciliary body C. Suspensory ligaments D. Choroid

B; The ciliary body contains ciliary muscle that attachs the lens through the suspensory ligaments, anchoring it in place.

The wall of the eye has three layers. The outermost fibrous layer is made up of the opaque white sclera and the transparent __________. A. lacrima B. choroid C. cornea D. ciliary gland

C

Where is the vitreous body located? A. Anterior chamber B. Anterior segment C. Posterior segment D. Posterior chamber

C; Correct. The vitreous body is the thick fluid that fills the back of the eyeball behind the lens.

Which cranial nerve carries visual information from the eyeball to the brain? A. Oculomotor nerve B. Olfactory nerve C. Vestibulocochlear nerve D. Optic nerve

D; Correct. Cranial nerve II, the optic nerve, carries sensory information from the eyeball to the brain.

Identify the fluid filled space between the cornea and iris. A. Anterior segment B. Posterior chamber C. Posterior segment D. Anterior chamber

D; Correct. The anterior chamber is the fluid filled space between the cornea and iris.

Which of the following structures is highly vascular? A. Sclera B. Cornea C. Retina D. Choroid

D; Correct. The choroid is the vascular layer. It is a membrane with a rich blood supply which nourishes the eye. It's dense blood supply gives the choroid a very dark color.

Identify the incorrect statement regarding the vitreous body. A. Supports the posterior surface of the lens B. Transmits light C. Holds the retina against the choroid D. Consists of a thin, watery fluid

D; Correct. The vitreous body is the gelatinous fluid that fills the posterior segment. The aqueous humor found in the anterior segment is a thin watery fluid.

The pupil can adjust its size independent of the iris. True False

false; Correct. The iris changes the diameter of the opening at its center, which is known as the pupil.

The iris divides the eye into the anterior and posterior segments. False True

false; Correct. The lens divides the eye into the anterior segment, located in front of the lens, and the posterior segment, located behind the lens.

At the optic chiasma, the fibers from the medial side of each eye cross over to the opposite side. True False

true

Only the fibrous layer can be observed in its entirety from the superficial surface of the cow eye. True False

true