Deck 36: Eye Structure

Question 1

Why is the optic disc sometimes called the blind spot of the eye?

A)There are no rods and cones there.
B)There are no nerve fibers there.
C)There are no blood vessels there.
D)There are rods there, but no cones, so color vision is not possible in that area.
E)There are cones there, but no rods, so black and white vision is not possible in that area.

Answer 1

A

Question 2

Vision is one of the special senses, because its receptors are found within complex sensory organs in the head.

Answer 2

True

Question 3

All of the following structures in the eye are black, due to the presence of melanin pigment, except

A)the choroid.
B)the ciliary body.
C)the retina.
D)the pigmented epithelium.
E)All of these eye structures are black, due to the presence of melanin pigment.

Answer 3

C

Question 4

Which of the following extrinsic eye muscles rotates the eyeball inferiorly and laterally?

A)Superior rectus
B)Inferior oblique
C)Inferior rectus
D)Superior oblique
E)Lateral rectus

Question 5

The conjunctiva is a mucous membrane that covers the entire anterior surface of the eyeball, including the cornea.

Question 6

Which portion of the lacrimal apparatus consists of 2 small pores that drain the tears off of the surface of the eye?

A)Lacrimal sac
B)Lacrimal gland
C)Nasolacrimal duct
D)Lacrimal puncta
E)Canaliculi

Question 7

In a sandstorm, which of the following muscles would protect the eyes, by closing the eyelids?

A)Levator palpebrae superioris
B)Orbicularis oculi
C)Superior rectus and inferior rectus
D)Lateral rectus and medial rectus
E)Superior oblique and inferior oblique

Question 8

Which of the following is NOT true of cones?

A)They provide for color vision.
B)Only cones are found in the fovea centralis.
C)Cones are much more numerous than rods in the peripheral portions of the retina.
D)Cones are responsible for sharp vision.
E)All of these are true of cones.

Question 9

What is the significance of the scleral venous sinus?

A)It produces the aqueous humor.
B)It drains blood from the inner layer of the eyeball.
C)It reabsorbs aqueous humor, to maintain proper pressure in the anterior cavity.
D)It produces the vitreous humor.
E)It reabsorbs vitreous humor, to maintain proper pressure in the posterior cavity.

Question 10

What is the function of the ciliary muscles?

A)They change the shape of the lens to accommodate near or far vision.
B)They change pupil diameter when lighting conditions change.
C)They close the upper eyelid.
D)They abduct the eye.
E)They open the upper eyelid.

Question 11

All of the following cranial nerves innervate the extrinsic eye muscles except

A)the facial nerve.
B)the abducens nerve.
C)the trochlear nerve.
D)the oculomotor nerve.
E)all of these cranial nerves innervate the extrinsic eye muscles.

Question 12

The innermost (most anterior)layer of the retina consists of

A)rods and cones.
B)bipolar neurons.
C)the pigmented epithelium.
D)nerve fibers of the ganglion cells.
E)amacrine cells.

Question 13

The pupil is an opening in the ciliary body, which allows light to enter the eye.

Question 14

The inner layer of the eye consists of the pigmented and neural portions of the

A)choroid and ciliary body.
B)retina and optic nerve.
C)lens and iris.
D)sclera and cornea.
E)lacrimal gland.

Question 15

What is the function of the suspensory ligaments?

A)They suspend the iris in the anterior cavity of the eye.
B)They hold the retina against the choroid.
C)They hold the optic nerve in place in the posterior portion of the eye.
D)They hold the lens in position, suspended from the ciliary body.
E)They hold the choroid against the sclera.

Question 16

Which structure of the cow (or sheep)eye is not present in humans, and helps to reflect light back through the retina, to provide good night vision?

A)Tarsal gland
B)Trochlea
C)Blind spot
D)Tapetum fibrosum
E)Ora serrata

Question 17

The aqueous humor occupies and flows through the anterior and posterior chambers and the pupil.

Question 18

Which of the following structures secrete(s)an oily lubricant for the surface of the eye?

A)Ciliary body
B)Lacrimal glands
C)Conjunctiva
D)Pigmented epithelium
E)Tarsal glands

Question 19

The area in which the nerve fibers of the retina leave the eye to become the optic nerve is called the

A)ora serrata.
B)ciliary process.
C)macula lutea.
D)trochlea.
E)optic disc.

Question 20

The anterior cavity of the eyeball is much smaller than the posterior cavity.