Exam 2: The Eye

Question 1

Lateral canthus & medial canthus

Answer 1

Corners where the two eyelids meet

Question 2

Eyelashes

Answer 2

Robust hairs that prevent foreign objects from reaching surface of eye

Question 3

Ocular conjunctiva

Answer 3

Clear membrane, converse the sclera (white part of eye), produces mucus, lubricates the eye

Question 4

Palpebral conjunctiva

Answer 4

Lines the inside of the eyelids

Question 5

Conjunctivitis

Answer 5

Inflammation of the conjunctiva

Can be caused by bacteria, virus, allergies such as hay fever & irritants in the environment

Question 6

Lacrimal apparatus

Answer 6

Produces, distributes & removes tears

Question 7

Eyelid

Answer 7

Continuation of skin

Blinking keeps surface of eye lunricated, washes dust & debris away

Question 8

Lacrimal gland (tear gland)

Answer 8

Secretions contain lysozyme (antibacterial enzyme)

Tears pass through:
2 lacrimal punctum 
2 lacrimal canaliculi 
Lacrimal sac
Nasolacrimal duct

Finally reach the inferior meat is of the nose

Question 9

Eyeball

Answer 9

Hollow

Divided into 2 cavities:
Smaller anterior cavity
Larger posterior cavity

Question 10

Three layers of the eye

Answer 10

Fibrous tunic: cornea & sclera
Vascular tunic: iris, ciliary body, choroid
Neural tunic: retina

Question 11

Cornea

Answer 11

Transparent front part of the eye

Contains unmyelinated nerves sensitive to touch, temp, & chemicals (corneal reflex)

Does not have blood vessels bc it receives nutrients via diffusion

Question 12

Sclera

Answer 12

Whites of the eye; contains collagen & elastic fibers

Question 13

Iris

Answer 13

Regulates amount of light entering eye; changes diameter of pupil

Contains muscle fibers

Question 14

Choroid

Answer 14

Provides route for blood & lymphatic vessels that supply tissues of eye

Vascular layer that separates fibrous & neural tunics

Delivers oxygen & nutrients to retina

Question 15

Papillary constrictor muscles (sphincter)

Answer 15

Decrease diameter of pupil

Question 16

Papillary constrictor muscles (radial)

Answer 16

Enlarges diameter of pupil

Question 17

Ciliary body

Answer 17

Controls shape of lens, essential for focusing

Secretes aqueous humor (clear liquid) that circulates w/I chambers of anterior cavity

Contains ciliary muscle which attach to suspensory ligaments of the lens

Question 18

Interior of eye (cavities/chambers)

Answer 18

Ciliary body & lens divide eye into:

Smaller anterior cavity (anterior & posterior chamber, filled with aqueous humor)

Large posterior cavity filled with vitreous humor

Question 19

Aqueous humor

Answer 19

Fluid circulates btwn lens & cornea (anterior cavity)

Exits via canal of schlemm

Enters circulation

Question 20

Ora serrata

Answer 20

The jxn btwn ciliary body & retina

Question 21

Retina

Answer 21

1. Outer pigmented part
2. Inner neural part: w/ receptors & interneurons

Cones and rods are the photoreceptors

Question 22

Rods

Answer 22

Do not discriminate colors, only black & white

Highly sensitive to light

Question 23

Cones

Answer 23

Red, green, & blue

Provide color vision

Densely clustered in fovea

Question 24

Visual axis

Answer 24

Imaginary line from center of object, through center of lens to fovea

Question 25

Optic disc (blind spot)

Answer 25

Circulation region just medial to fovea Origin of optic nerve & vessels

Question 26

Visual pathway

Answer 26

1. Axons from retina 2. Optic nerve (ll) 3. Optic chiasm 4. Lateral geniculate nucleus 5. Super colliculus 6. Ends at visual cortex

Question 27

Fovea

Answer 27

Area of clearest vision