1: UII CN II

Question 1

What is the outer most layer of the eye called?

Answer 1

Fibrous tunic

Question 2

What is the fibrous tunic made of?

Answer 2

Sclera: white part
Cornea: clear part over color

Question 3

What is the only complete layer of the eye?

Answer 3

The outer fibrous tunic

Question 4

What is the primary refractory structure of the eye that focuses light on the correct area?

Answer 4

Cornea

Question 5

What is the middle layer of the eye called?

Answer 5

Vascular tunic

Question 6

What is the vascular tunic made of?

Answer 6

Ciliary body: ciliary muscle and ciliary organs
Iris: colored part with 2 muscles
Choroid: highly vascular

Question 7

What is the inner most layer of the eye?

Answer 7

Retina

Question 8

How many layers does the retina have?

Answer 8

10 layers

Question 9

What are the 10 layers of the eye from inside to outside?

Answer 9

Internal limiting membrane
Nerve fiber layer
Ganglion cell layer
Inner plexiform layer
Inner nuclear layer
Outer plexiform layer 
Outer nuclear layer
External limiting layer 
Photosensitive outer segment 
Pigmented layer

Question 10

What is the pigmented layer adjacent to?

Answer 10

The choroid

Question 11

What is the photosensitive layer made of?

Answer 11

Outer segments of rods and cones

Question 12

What does the outer nuclear layer contain?

Answer 12

Rod and cone cell bodies

Question 13

What happens in the outer plexiform layer?

Answer 13

Rods and cones synapse with bipolar cells here

Question 14

What does the inner nuclear layer contain?

Answer 14

Cell bodies of bipolar cells

Question 15

What happens in the inner plexiform layer?

Answer 15

Bipolar cells synapse with ganglion cells here

Question 16

What is contained in the ganglion cell layer?

Answer 16

Ganglion cell bodies

Question 17

What is the nerve fiber layer made of?

Answer 17

Retinal ganglion cell axons

Question 18

Are retinal ganglion cell axons myelinated?

Answer 18

No… Unmyelinated

Question 19

What is the internal limiting membrane?

Answer 19

Glial boundary separating the retina from the vitreous body

Question 20

What shapes can the distal end of photoreceptors (closest to choroid) be?

Answer 20

Cylindrical (rod) shape

Tapered (cone) shape

Question 21

How many types of cones are there?

Answer 21

3: red, green, blue

Question 22

What do the cones recieve?

Answer 22

Color information (can sharpen image)

Question 23

What do the cones require to function properly

Answer 23

Adequate light

Question 24

Where are cones more concentrated?

Answer 24

Toward center of retina (fovea)

Question 25

How is color blindness genetic?

Answer 25

Fewer cones = greater color blindness | Mom carries, 23 chromosome, sex linked

Question 26

What do rods sense?

Answer 26

Light vs. dark only

Question 27

Where are rods found?

Answer 27

Periphery of retina al list all rods

Question 28

Are rods found in the fovea?

Answer 28

NO

Question 29

How do depolarized photoreceptors relay info?

Answer 29

To bipolar cells in outer plexiform layer

Question 30

Where are bipolar cell bodies found?

Answer 30

Inner nuclear layer

Question 31

What type of cells do bipolar cells relay info to?

Answer 31

Ganglion cells

Question 32

What layer do bipolar cells synapse with ganglion cells

Answer 32

Inner plexiform layer

Question 33

How do axons from ganglion cells travel?

Answer 33

In optic nerve from eye to optic disc

Question 34

How does the optic nerve enter the skull?

Answer 34

Through the optic canal, unite to form optic chiasma

Question 35

Are there photoreceptors on the optic disc?

Answer 35

NO

Question 36

Are the optic nerve fibers myelinated?

Answer 36

Yes

Question 37

What cells form the myelin on the optic nerve (CN II)

Answer 37

(Interfasciular) olgiodendrocytes

Question 38

Which fibers of CN II cross in the optic chiasma

Answer 38

Medial side of retina

Question 39

Which fibers of CN II do not cross in the optic chiasma?

Answer 39

The lateral retina fibers

Question 40

After CN II fibers split and cross in the optic chiasma what is formed?

Answer 40

Optic tracts

Question 41

How do the optic tracts travel?

Answer 41

Around the cerebral peduncles, fibers synapse on 1/3 nuclei of termination

Question 42

What are the three nuclei of termination that the optic tracts can synapse on?

Answer 42

Lateral geniculate body, superior colliculus, tectospinal tract

Question 43

How many layers is the eye made of?

Answer 43

Three layers

Question 44

How do the majority of CN II fibers travel?

Answer 44

Synapse in the lateral geniculate body, relayed to the cerebral cortex in the occipital lobe (BMA 17)

Question 45

How are the superior colliculus and tectospinal tract related?

Answer 45

Fibers synapse in the superior colliculus and info is relayed to the tectospinal tract

Question 46

What two muscles are influenced by the tectospinal tract?

Answer 46

Trapezius and sternocleidomastoid

Question 47

What is observed with optic nerve lesion?

Answer 47

Lose sight in the eye the lesion is on, lose depth perception

Question 48

What is observed with a lesion in the optic chiasma?

Answer 48

Tunnel vision, loss of peripheral vision

Question 49

What is observed with a lesion in the optic tract?

Answer 49

Lose 1/2 of vision on the opposite side of the lesion

Question 50

What is the direct and consensual light reflexes?

Answer 50

Side with light constricts a lot: DIRECT | Side with out light slightly constricts: INDIRECT

Question 51

What is the accommodation reflex?

Answer 51

Near/far | Increase in convexity = closer focus

Question 52

What is the corneal reflex?

Answer 52

Touch cornea: person blinks and pulls away

Question 53

What is the convergence reflex?

Answer 53

Look at nose

Question 54

What are you testing with cranial nerve II reflex tests?

Answer 54

AFFERENT components only (CN II purely sensory) | Response requires motor function through different cranial nerve