Exercise 24

Question 1

Lacrimal gland

Answer 1

Produces and secretes tears onto eye surface

Question 2

Lacrimal canal

Answer 2

Drains tears from eyes into lacrimal sac

Question 3

Conjunctivitis

Answer 3

AKA pink eye. Inflammation of the bulbar conjunctiva. Viral, sometimes bacterial infection. Very contagious, more common in children

Question 4

Bulbar conjunctiva

Answer 4

Protective mucous membrane that covers anterior part of white of eye BUT NOT CORNEA

Question 5

Fibrous tunic

Answer 5

Cornea & sclera. Provides structural shape of eye

Question 6

Cornea

Answer 6

Transparent, avascular, allows light to enter through pupil

Question 7

Astigmatism

Answer 7

Caused by irregularities in the curvature of cornea or lens causing parts of image to be blurry

Question 8

Sclera

Answer 8

White of eye, forms most of eyeball

Question 9

Sclearal venous sinus (SVS)

Answer 9

AKA canal of Schlemm. Opening found at the junction of the cornea and sclera. FUNCTION: Collects aqueous humor from anterior chamber and delivers it into bloodstream via anterior ciliary veins

Question 10

Vascular tunic

Answer 10

Iris, ciliary body, choroid. Contains blood vessels

Question 11

Iris

Answer 11

Smooth muscle, controls size of pupil. Contains melanin, forms eye color.

Question 12

Pupils

Answer 12

Opening that allows light to enter the vitreous chamber to reach the central fovea of the macula lutea of the retina which affects focus

Question 13

Ciliary body

Answer 13

Ciliary muscle & ciliary process

Question 14

Ciliary muscle

Answer 14

Smooth muscle that changes shape of the lens

Question 15

Ciliary process

Answer 15

Attached to suspensory ligaments that are attached to the lens. Produces aqueous humor

Question 16

Aqueous humor

Answer 16

Fluid located in the anterior cavity of the eye. Produced by ciliary process & drained by scleral venous sinus back into blood. Provides nutrients & oxygen, removes waste products for lens & cornea

Question 17

Anterior cavity

Answer 17

Anterior chamber & posterior chamber. Between cornea & lens. Contains aqueous humor produced by capillaries in ciliary process

Question 18

Anterior chamber

Answer 18

Between cornea & iris

Question 19

Posterior chamber

Answer 19

Between iris & lens

Question 20

Choroid

Answer 20

Contains blood vessels, nourishes retina. Contains tapetum (green-blue, night vision, not found in humans)

Question 21

Sensory tunic

Answer 21

Retina. Contains neural tissue from outgrowth of the brain

Question 22

Retina

Answer 22

Pigmented layer & 3 layers of neurous: photoreceptor, bipolar cell, ganglion cell. Nervous tissue. Used to communicate visual information to the brain.

Question 23

Photoreceptor layer

Answer 23

Deepest neural layer. Contains rods (black & white images) & cones (color images)

Question 24

Bipolar cell layer

Answer 24

Middle neural layer

Question 25

Ganglion cell layer

Answer 25

Superficial neural layer. Contains neurons whose axons exit eye as optic nerve

Question 26

Lens

Answer 26

Important for focusing images. Avascular & made of proteins that are transparent. Divides interior of eye ball into 2 cavities: anterior cavity (anterior & posterior chamber) & vitreous chamber (posterior cavity)

Question 27

Cataract

Answer 27

Loss of transparency of the lens

Question 28

Causes of cataract formation

Answer 28

Age, diabetes

Question 29

Glaucoma

Answer 29

Most common kind of blindness. Can occur if aqueous humor fails to drain out the scleral venous sinus causing increase in pressure within anterior cavity of eye called intraocular pressure. Fluid compressed lens into posterior cavity & puts pressure on neurons of retina

Question 30

Vitreous chamber

Answer 30

Posterior cavity. Space between lens & retina filled with vitreous body (thick gel-like substance) which holds retina flat against choroid

Question 31

Macula lutea

Answer 31

Center of neural portion of retina (site of macular degeneration)

Question 32

Macular degeneration

Answer 32

Age-related macular disease. Generative disorder of retina in people over 50. Lose ability to see straight ahead (peripheral vision retained). 2 types: "dry" AMD: pigmented layer of retina atrophies & degenerates. "wet" AMD: new blood vessels form in choroid & leak plasma or blood under retina (laser surgery used to destroy leaking blood vessels)

Question 33

Central fovea (fovea centralis) of macula lutea

Answer 33

Located in middle of macula lutea. Where image is best focused on retina. Highest concentration of photoreceptors. No ganglion or bipolar cells

Question 34

Optic disc

Answer 34

AKA blind spot. Region of optic nerve & blood vessels. No photoreceptors hence "blind" spot

Question 35

Optic nerve

Answer 35

Nervous tissue of retina exits eyeball as optic nerve

Question 36

Which lobe of brain interprets information for vision?

Answer 36

Occipital lobe

Question 37

Visual pathway

Answer 37

Optic nerve (axons of ganglion cells) -> optic chiasm -> optic tract -> primary visual area of cortex in occipital lobe of brain

Question 38

Detached retina

Answer 38

Can occur due to trauma or age-related macular degeneration. Deteachment occurs between neural portion of retina & pigmented epithelium

Question 39

Color blindness

Answer 39

Inherited inability to distinguish between certain colors. Results from absence or deficiency of one of the three types of cones.

Question 40

Most common color blindness

Answer 40

Red-green color blindness. Red or green cones missing