Lecture 27 - Neuroanatomy of Visual Pathway

Question 1

What is the pathway of light?

Answer 1

Cornea, iris, lens, and retina

Question 2

What is light captured by in the eye?

Answer 2

Specialized epithelial cells in the retina

Question 3

What are the names of the photoreceptors in the eye?

Answer 3

Rods and cones

Question 4

What does light pass through before getting to the photoreceptors?

Answer 4

Many non-photosensitive neural layers

Question 5

What are the layers of the retina? (A to P)

Answer 5

Optic nerve fibers - Cell bodies of retinal ganglion n. - Internal nuclear layer - External nuclear layer - Outer and inner segments of photoreceptors - pigment epithelium

Question 6

What do rods sense?

Answer 6

Vision in light of low intensity

Question 7

How many types of rods are there?

Answer 7

one

Question 8

What do cones sense?

Answer 8

Visual activity and color vision

Question 9

What are the types of cones?

Answer 9

Short and medium

Question 10

What are cones sensitive to?

Answer 10

Wavelengths

Question 11

Where are robs mostly located?

Answer 11

Periphery of retina

Question 12

What is the ratio of rods to bipolar neurons?

Answer 12

Many rods : Biopolar neuron

Question 13

What is the ratio of cones to bipolar neurons?

Answer 13

Few cones : Bipolar neruon

Question 14

What is within the internal nuclear layer?

Answer 14

Cell bodies of bipolar neurons and other neurons

Question 15

What is within the external nuclear layer?

Answer 15

Cell bodies of photoreceptors

Question 16

What does 3 cones at higher density provide?

Answer 16

Higher acuity

Question 17

What does 2 cones at lower density provide?

Answer 17

Higher sensitivity

Question 18

What do human rods provide?

Answer 18

Spatial detail but darker image

Question 19

What do feline rods provide?

Answer 19

Higher sensitivity or brighter image

Question 20

What is the basic retinal pathway?

Answer 20

Photoreceptors - Bipolar neurons - Retinal ganglion neurons

Question 21

What is the “path” of the optic nerve?

Answer 21

Nerve - Chiasm - Tract

Question 22

What is the function of the optic nerve?

Answer 22

Relay information from retinal ganglion cells to the lateral geniculate nucleus

Question 23

Where is the geniculate nucleus?

Answer 23

In the thalamus

Question 24

What surrounds the retinal ganglion cells?

Answer 24

Meninges

Question 25

What is the retinogeniculostriate pathway?

Answer 25

Retinal ganglion - lateral geniculate nucleus of thalamus - primary visual cortex

Question 26

What are the three structure formations in the occipital lobe?

Answer 26

Loop of meyer, optic radiation (ventral and dorsal)

Question 27

Where is the optic radiation of the ventral part?

Answer 27

Temporal lobe

Question 28

Where is the optic radiation of the dorsal part?

Answer 28

Parietal lobe

Question 29

Which tract does the nasal field of the right eye go?

Answer 29

Right optic tract

Question 30

Which tract does the temporal field of the right eye go?

Answer 30

Left optic tract

Question 31

Where do the temporal fields cross?

Answer 31

Optic chiasm

Question 32

What happens if there is a lesion in the optic nerve?

Answer 32

Blindness in that eye

Question 33

What happens if there is a lesion in the optic chiasm?

Answer 33

Loss of temporal field

Question 34

What happens if there is a lesion in the optic tract?

Answer 34

Loss of temporal field in opposite eye and loss of nasal field in same eye