The Eye

Question 1

___, one of the special senses, relies on a very complex receptor apparatus: the eye.

Answer 1

Vision

Question 2

____ depends on a variety of positioning and focusing mechanisms to form an image in the correct spot on the light-sensitive receptor cells inside the eye.

These mechanisms involve muscles, lenses, and other structures that are all a part of the visual apparatus.

The complexity of structure allows for complexity of function.

Answer 2

Vision

Question 3

The visual image perceived by humans has the qualities of

Answer 3

resolution, brightness, color, and depth.

Question 4

The ____ and its accessory structures provide the structural apparatus required for processing and receiving visual images.

Answer 4

human eye

Question 5

What are lacrimal apparatus ?

Answer 5

Lacrimal gland
Nasolacrimal duct

Question 6

Exocrine “tear” gland in the superior lateral corner of the orbit

Answer 6

Lacrimal gland

Question 7

Duct in the inferior medial corner of the orbit, drains tears from lacrimal canals toward the nasal cavity

Answer 7

Nasolacrimal duct

Question 8

Extrinsic eye muscle

Superior, inferior, medial, lateral

Answer 8

Rectus muscles. (four)

Question 9

Extrinsic eye muscle

Superior, inferior

Answer 9

Oblique muscles (two)

Question 10

Thin, transparent mucous membrane adhering to the anterior surface of the eye and lining the eyelids

Answer 10

Conjunctiva

Question 11

Layers of the eyeball

Answer 11

Fibrous layer
Vascular layer
Inner layer

Question 12

Fibrous layer (outer coat)

The ___ is the anterior, transparent portion. The ___ is the white, fibrous portion.

Answer 12

cornea, sclera

Question 13

Vascular layer (middle coat)

The posterior portion is the thin, heavily pigmented ___. The anterior portions include the circular ___, in which are incorporated the ciliary muscles (intrinsic eye muscles).

Answer 13

choroid, ciliary body

Question 14

The ciliary muscles are attached to the rim of the lens by means of
____

Answer 14

suspensory ligaments.

Question 15

To bend the light to focus it on the retina

Answer 15

Eye lenses

Question 16

Attached to the anterior edge of the ciliary body is the colored iris, which has an opening called the ___.

Answer 16

pupil

Question 17

The ___ of your eye is the black hole in the middle of your iris.

Answer 17

pupil

Question 18

Your ___ is the colored part of your eye

Answer 18

iris

Question 19

• Inner layer (inner coat) -

The retina is divided into two layers:

Answer 19

the outer pigmented retina and the inner sensory retina.

Question 20

The ___ contains photoreceptor cells of two main types— rods and cones —as well as association neurons.

Answer 20

sensory retina

Question 21

In the posterior retina is a small, yellow macula lutea with a pit called the ___.

Answer 21

fovea centralis

Question 22

The ___ is normally the center of the visual field and contains many cones.

Answer 22

fovea

Question 23

are specialized cells in the retina that convert light into signals the brain uses for vision.

Answer 23

Rods and cones

Question 24

___ become more dominant farther away from the fovea.

Answer 24

Rods

Question 25

Medial to the macula lutea is the white ___. Here, blood vessels, as well as the nerve fibers that exit as the optic nerve, pass out of the eyeball.

Answer 25

Optic disk

Question 26

is a yellow oval spot in the center of the retina that provides sharp, detailed central vision. It’s also known as the fovea

Answer 26

macula lutea

Question 27

These cells are concentrated near the fovea, the central area of the retina.

They are less sensitive to light than rods but have higher temporal resolution.

___ are responsible for color vision and can adapt quickly to changes in light. There are three types of it, each sensitive to different wavelengths of light: long (red), medium (green), and short (blue).

Answer 27

Cones

Question 28

These cells are more numerous and located in the periphery of the eye. They are highly sensitive to light and are responsible for night vision and peripheral vision. __ detect shades of gray but do not discern color.

Answer 28

Rods

Question 29

Filled with aqueous humor, a watery filtrate produced by the ciliary body.

Aqueous humor circulates from the posterior chamber behind the iris, through the pupil, and to the anterior chamber, where it is reabsorbed.

Answer 29

Anterior cavity

Question 30

Filled with transparent, jelly-like vitreous body. This cavity is posterior to the lens.

Answer 30

Posterior cavity

Question 31

The nerve bundle projecting from the posterior of the eyeball

Answer 31

Optic nerve

Question 32

These may have been cut from your specimen during preparation

Answer 32

Extrinsic eye muscles (six)

Question 33

The white portion of the vascular layer

Answer 33

Sclera

Question 34

The clear, anterior portion of the vascular layer

Answer 34

Cornea

Question 35

The pigmented region under the cornea

Answer 35

Iris

Question 36

The iris’s hole (it may be oblong in your specimen rather than round as in the human)

Answer 36

Pupil

Question 37

The thin mucous membrane over the anterior portion of the eye, extending to line the inner eyelid

Answer 37

Conjunctiva

Question 38

The thick jelly-like substance of the posterior cavity

Answer 38

Vitreous body

Question 39

A watery liquid in the anterior cavity

Answer 39

Aqueous humor

Question 40

A plastic-like ball of translucent tissue (in fresh specimens it is very clear; hold it up and try to look through it)

Answer 40

Lens

Question 41

A ring of ridges around the outside of the iris’s margin (the ridges are formed by the ciliary muscles within

Answer 41

Ciliary body

Question 42

A thin film of gray matter loosely associated with the inside posterior wall of the eyeball (it may have fallen away, appearing as a crumpled mass still attached at the optic disk)

Answer 42

Retina

Question 43

The pigmented region of the vascular layer in the posterior region of the eyeball’s wall, deep to the sclera and superficial to the retina.

Answer 43

Choroid -

Question 44

In some mammals but not in humans, an ___ can be seen in the choroid.

Answer 44

iridescent tapetum lucidum