Week 2 - Sight

Question 1

Name all 6 extrinsic eye muscles

Answer 1

• Superior rectus
• Lateral rectus
• Medial rectus
• Inferior rectus
• Superior oblique
• Inferior oblique

Question 2

Cornea: What, where and function

Answer 2

What: Transparent layer that cover iris
Where: Front of eye, bulges out; covers iris
Function: Helps to focus light through pupil

Question 3

Lens: What, where and function

Answer 3

What: Transparent membrane
Where: Within the eye behind pupil and iris; bulges IN
Function: Focuses images onto the retina to produce clear vision

Question 4

Retina: What, where and function

Answer 4

What: Nervous tissue membrane
Where: Innermost layer of eye
Function: Converts light rays into nerve impulses to be translated by brain

Question 5

Sclera: What, where and function

Answer 5

What: White fibrous tissue
Where: Outermost part of eye
Function: Protects and shapes eyeball, insertion site for eye muscles

Question 6

Choroid: What, where and function

Answer 6

What: Thin, dark brown, vascular membrane
Where: Beneath the sclera
Function: Provides nutrients to posterior surface of the retina

Question 7

Cilliary body: What, where and function

Answer 7

What:
Where: Anterior portion of the eye
Function: Secretes aqueous humor; changes tensions of zonular fibers to adapt lens for near or far vision

Question 8

Iris: What, where and function

Answer 8

What: Colored part of the eye
Where: Between cornea and lens (The middle of outward and inward bulge)
Function: Regulates the amount of light that flows through pupil

Question 9

Front to Back:

Answer 9

Cornea-Iris-Lens

Question 10

Layers: Outside-In

Answer 10

Sclera-Choroid-Retina-Cilliary Body (Anterior)

Question 11

List the Lacrimal Pathway

Answer 11

Lacrimal glands-Excretory ducts-Eyelid/Eyeball-Lacrimal canaliculi-Lacrimal sac-Nasolacrimal duct

Question 12

Vitreous Body: What, where and function

Answer 12

What: Inner bulb of eye
Where: Between lens and the retina of the eye
Function: Holds retina against choroid to provide flat, even surface

Question 13

Optic Nerve / CN II

Answer 13

What: CN II
Where: Originates in retina of eyes; connects to optic disc
- Pass through optic foramen of sphenoid –> converges at optic chiasm –> forms optic tracts
Function: Transmits signals for vision

Question 14

Optic disc

Answer 14

What: Where optic nerves exit the eye
Where: Back of the eye
Function: Where optic nerves exit the eye

Question 15

Fovea centralis in macula lutea

Answer 15

What: small depression in the retina
Where: Macula lutea; posterior and lateral (same side of eye)
Function: High visual acuity due to highest density of cones

Question 16

Photoreceptor cells: Location and function

Answer 16

• Located in the retina
• About 120 millions rods and 6 millions cones
• Rods detect dim light, no color
• Cones detect bright light and color

Question 17

Myopia/nearsightedness: Cause and what it is

Answer 17

• Caused by an eyeball that is too long
• can see close, but not distant

Question 18

Hyperopia/Farsightedness: Cause and what it is

Answer 18

• Caused by an eyeball that is too short
• Can see distant but not close

Question 19

Prebyopia/Old person’s farsightedness

Answer 19

The loss of accomodation to focus on nearby objects with age

Question 20

Astigmatism

Answer 20

Imperfection in the curvature of the eye that causes blurred distance and near vision

Question 21

Optic Chiasm

Answer 21

What: Crossing point of the optic nerve
Where: Base of the hypothalamus
Function: Allows information to pass from left side of each eye to right and vice versa.