Chap 16 - The Eye Part 1

Question 1

Function of accessory structure:

Eyebrows

Answer 1

prevent sweat from dripping into open eyes

Question 2

Function of accessory structure:

Eyelids (palpebrae)

Answer 2

Mobile Anterior covering of eye surface

Question 3

Function of accessory structure:

Palpebral fissure (eyelid slit)

Answer 3

Separates eyelid

Question 4

Function of accessory structure:

Medial and lateral commisures (canthi)

Answer 4

Eyelid United at

Question 5

Function of accessory structure:

Tarsal plates

Answer 5

Anchor muscles that run within the eyelid

Question 6

Function of accessory structure:

Tarsal glands

Answer 6

Produce secretion to lubricate the eyelids

Question 7

Function of accessory structure:

Eyelashes

Answer 7

Prevent objects from co in To contact with eye

Question 8

3 Function of accessory structure:

Conjunctiva

Answer 8

Lubricate and moisten the eye

supply nutrients to avascular sclera

Contains abundant nerve endings

Question 9

Components of lacrimal apparatus

Answer 9

Lacrimal gland

Lacrimal puncta

Nasolacrimal duct

Question 10

Lacrimal gland function

Answer 10

continuously produces lacrimal fluid

Question 11

Lacrimal puncta function

Answer 11

drain lacrimal fluid

Question 12

Nasolacrimal duct function

Answer 12

drains fluid into lateral side of nasal cavity

Question 13

The six extrinsic eye muscles

Answer 13

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

Question 14

Lateral rectus function

Answer 14

Moves eye laterally

Question 15

Medial rectus function

Answer 15

Moves eye medially

Question 16

Superior rectus function

Answer 16

Elevates eye and turns it medially

Question 17

Inferior rectus function

Answer 17

Depresses eye and turns it medially

Question 18

Inferior oblique function

Answer 18

Elevates eye and turns it laterally

Question 19

Superior oblique function

Answer 19

Depresses eye and turns it laterally

Question 20

Formula to remember muscle eye innervation

Answer 20

[(SO4)(LR6)]3

Question 21

Sclera structure and 2 function

Answer 21

composed of dense irregular connective tissue provides eye shape
protects eye’s internal components

Question 22

Cornea structure

Answer 22

inner simple squamous epithelium
Middle layer of collagen fibers
outer stratified squamous epithelium

Question 23

Choroid structure and function

Answer 23

houses vast capillaries supporting the retina

cells filled with pigment from melanocytes pigment absorbs light, preventing it from scattering and reflecting within the eye

Question 24

Retina structure

Answer 24

Outer pigmented layer and inner neural layer

Question 25

Pigmented layer function

Answer 25

light rays passing through inner layer absorbed here

Question 26

Ciliary body structure

Answer 26

composed of ciliary muscles and ciliary processes

Question 27

Suspensory ligaments structure and function

Answer 27

suspensory ligaments extending from muscle to lens | contraction changing tension on ligaments, altering lens shape

Question 28

Iris structure

Answer 28

two layers of pigment-forming cells | two groups smooth muscle fibers

Question 29

Pupil structure and function

Answer 29

black opening at center of iris | controls amount of light entering the eye

Question 30

Macula lutea structure

Answer 30

rounded, yellowish region lateral to optic disc

Question 31

Macula lutea contains?

Answer 31

contains fovea centralis

Question 32

List the 5 layers of neural retina from posterior to anterior side

Answer 32

1- First posterior layer is made of rods & cones photoreceptors. 2- Next layer is made of horizontal cells for lateral integration. 3- Bipolar cells 4- Amacrine cells (ama=without axons) for lateral integration. 5- Ganglion cells (anterior)

Question 33

The optic nerve consist of the axons of the _________ cells of the retina

Answer 33

Ganglion

Question 34

The _______ ________ is the site where the optic nerve leaves the eye

Answer 34

Optic disc

Question 35

Why can't you see at the optic disc?

Answer 35

No rods or cones

Question 36

What are the structures that the light passes by from an object outside the eye until it reaches the photoreceptors of the retina

Answer 36

air, cornea, aqueous humor lens, vitreous humor, inner two layers of retina

Question 37

Problems of refraction?

Answer 37

Myopia Hyperopia Astigmatism Presbyopia

Question 38

Myopia what? Corrected?

Answer 38

Myopia (nearsightedness)— focal point is in front of the retina Concave lens

Question 39

Hyperopia what? Corrected?

Answer 39

Hyperopia (farsightedness) —focal point is behind the retina Corrected with convex lens

Question 40

Astigmatism what? Corrected?

Answer 40

Unequal curvatures of the Cornea Corrected with special lenses, corneal implants, and laser surgery

Question 41

Presbyopia what! Corrected?

Answer 41

Lens less able to become spherical Convex lens Surgery

Question 42

Differences between rods and cones in regards to: Anatomy

Answer 42

Cones are shorter and wider than rods

Question 43

Differences between rods and cones in regards to: Their photopigments

Answer 43

Rhodopsin in rods Photopsin In cones

Question 44

Differences between rods and cones in regards to: What light they process

Answer 44

Rods bright light Cones dim light

Question 45

Describe visual pathway from the photoreceptors to the brain

Answer 45

1. Light (photons) activates visual pigment. 2. Visual pigment activates transducin 3. Transducin activates phosphodiesterase (PDE). 4. PDE converts cGMP 5. As cGMP levels fall, cGMP-gated cation channels close, resulting in hyperpolarization.

Question 46

Cataracts

Answer 46

Clouding of lens

Question 47

Macular degeneration

Answer 47

–Physical deterioration of macula lutea

Question 48

Detached retina

Answer 48

Occurs when outer pigmented and inner neural layers separate –Symptoms of “floaters” in affected eye

Question 49

Conjunctivitis (pink eye) Symptoms Causes

Answer 49

Inflammation and reddening of the conjunctiva | Due to viral infection, bacterial infection,

Question 50

Trachoma Cause

Answer 50

•caused by Chlamydia trachomatis | common cause of neonatal blindness in developing countries

Question 51

Glaucoma | Characterized by

Answer 51

Characterized by increased intraocular pressure

Question 52

Diplopia

Answer 52

Double vision

Question 53

Strabismus

Answer 53

Cross eyed

Question 54

What are three layers (tunics) of eye

Answer 54

Fibrous Vascular Nervous

Question 55

Macula lutea what is it?

Answer 55

depressed pit –highest proportion of cones and few rods

Question 56

Macula lutea function?

Answer 56

area of sharpest vision