Chapter 23: The Eye

Question 1

Highly developed photosensitive organs for analyzing the form, intensity, and color of light reflected from objects and providing the sense of sight

Answer 1

Eyes

Question 2

The eye is composed of three concentric tunics or layers called: ___,___, and ___

Answer 2

Fibrous, Vascular, and Retina

Question 3

At tough external fibrous layer consisting of the ____ and the transparent _____

Answer 3

Sclera; cornea

Question 4

A middle vascular layer consisting of the ____, ____ body, and ___

Answer 4

Choroid, ciliary Body, and iris

Question 5

An inner sensory layer, retina, which communicates with the _____ through the posterior ____ nerve

Answer 5

Cerebrum; optic nerve

Question 6

The sclera consists mainly of _____ CT, with flat bundles of ____ _ _____, moderate ground substance, and fibroblasts

Answer 6

Dense; type I collagen

Question 7

Attachment site for tendons of the extraocular muscles which move the eyes

Answer 7

Sclera

Question 8

Joins the epineurium covering the optic nerve

Answer 8

Sclera

Question 9

Cornea layer: external corneal epithelium, which is ______ _____ epithelium

Answer 9

Stratified squamous

Question 10

Cornea layer: an anterior limiting membrane called ____ ______, which is the basement membrane beneath the corneal epithelium

Answer 10

Bowman membrane

Question 11

Cornea layer: the middle layer and thickest

Answer 11

Stroma

Question 12

Cornea layer: a posterior limiting membrane, called _____ _____, which is the basement membrane of the endothelium

Answer 12

Descemet membrane

Question 13

Cornea layer: the inner most layer; _____ ____ endothelium

Answer 13

Simple squamous endothelium

Question 14

The stroma consists of _____ and between those cytoplasmic extensions of flattened fibroblast-like cells called _____

Answer 14

Collagen; keratocytes

Question 15

Encircling the cornea is the ______, a transitional area where the transparent cornea merges with the opaque sclera

Answer 15

Limbus

Question 16

The most anterior extension of the vascular layer (middle layer) which covers part of the lens

Answer 16

Iris

Question 17

The anterior surface of the iris consists of a dense layer of _________ and _______ and loose CT

Answer 17

Fibroblasts and melanocytes

Question 18

The posterior layer of the iris has a two-layered _______ heavily filled with melanin

Answer 18

Epithelium

Question 19

The _____ and ______ pupillary muscles of the iris have sympathetic and parasympathetic innervation, respectively, for enlarging and consisting the pupil

Answer 19

Dilator and sphincter

Question 20

____ a transparent biconvex structure suspended immediately behind the iris, which focuses light on the retina

Answer 20

Lens

Question 21

Derived from the embryonic surface ______, the lens is ________ tissue and is highly elastic, a property that normally decreases with age

Answer 21

Ectoderm; avascular

Question 22

The lens had three components: ____, _____, and ____

Answer 22

Capsule, epithelium, and fibers

Question 23

The lens ____ originates as the basement membrane of the embryonic lens vesicle

Answer 23

Capsule

Question 24

The lens capsule provides the place of attachment for ____ ______ fibers

Answer 24

Ciliary zonule (zonular)

Question 25

The lens _______ consist of a single layer of cubical cells present only on the anterior surface of the lens

Answer 25

Epithelium

Question 26

Lens ____ are highly elongated, terminally differentiated cells with no nuclei

Answer 26

Fibers

Question 27

The cytoplasm of the lens fibers become filled with a group of proteins called _____

Answer 27

Crystallins

Question 28

The ____ ____, the anterior expansion of the vascular layer that encircles the lens

Answer 28

Ciliary body

Question 29

The ____ ____ consists of smooth muscle and loose CT and is very vascular

Answer 29

Ciliary muscle

Question 30

Fluid flows across the eye into the adjacent larger space called ____ __ ______

Answer 30

Canal of Schlemm

Question 31

The _____ is a vascular tissue, with many melanocytes that prevent light from entering the eye except through the pupil; part of vascular layer

Answer 31

Choroid

Question 32

Layer which provides nutrition for the retina

Answer 32

Choroid

Question 33

The ____, the innermost layer of the eye, develops with two sublayers from the embryonic optic cup

Answer 33

Retina

Question 34

Cells extremely sensitive to light

Answer 34

Rod cells

Question 35

Rods: Proteins on the cytoplasmic surface of each disc include abundant _____ or visual purple

Answer 35

Rhodopsin

Question 36

____ cells produce color vision adequately bright light

Answer 36

Cone cells

Question 37

Each visual pigment (iodopsin) contains a transmembrane protein, the ____, with a small, light-sensitive chromophore molecule bound to it. The vitamin A derivative called _____ acts as the chromophore of rhodopsin in rods

Answer 37

Opsin; retinal

Question 38

All neurons of the retina are supported metabolically by elongated, regularly arranged glial cells called _____ cells

Answer 38

Müller cells

Question 39

The _______ is a thin, transparent mucosa that covers the exposed, anterior portion of the sclera and continues as the lining on the inner surface of the eyelids =

Answer 39

Conjunctiva

Question 40

Consists of goblet cells; mucous secretions help coat its epithelium and the cornea

Answer 40

Conjunctiva