Lecture 1/4

Question 1

rods are ___ microns in length

Answer 1

100 microns

Question 2

are rods shorter or longer than cones?

Answer 2

rods are longer than cones

Question 3

example of the “funnel” ratio in the neural connections of the rods

Answer 3

10 rods: 5 bipolar : 1 ganglion

Question 4

funnel shape arrangement of the rod wiring has what effects?

Answer 4

• decreased discrimination

- increased sensitivity

Question 5

outer segment of photoreceptor is ___ microns in length

Answer 5

25 microns in length

about 1/4 the total length

Question 6

photopigment in rod outer segment is:

Answer 6

rhodopsin

Question 7

rhodopsin is coated on discs which are piled up in the outer segment. how many discs are there?

Answer 7

700-1000 discs piled up

Question 8

the function of the inner segment of the photoreceptors is:

Answer 8

for metabolism

Question 9

describe the connection between the inner and outer segment of the photoreceptors

Answer 9

connected by a cilium, which is a small slender tube (packed with microtubules)

Question 10

the inner segment is made up of what 2 components?

Answer 10

• ellipsoid

- myoid

Question 11

what does the ellipsoid of the inner segment contain?

Answer 11

high concentration of mitochondria (for energy)

Question 12

what does the myoid of the inner segment contain?

Answer 12

vesicles containing endoplasmic reticulum, golgi apparatus, and ribosomes

Question 13

what is the purpose of the outer conducting fiber?

Answer 13

connects inner segment to the cell body

Question 14

nucleus of the rod is ___ microns

Answer 14

5 microns

Question 15

which is smaller- the nucleus of the rod or cone?

Answer 15

the nucleus of the rod is smaller

Question 16

which is farther away from the ELM- the nucleus of the rod or nucleus of the cone?

Answer 16

the nucleus of the rod is farther away from the ELM

Question 17

purpose of the inner conducting fiber:

Answer 17

from the cell body to the synapse that ends in a foot plate

Question 18

foot plate in the rods is called _____

Answer 18

Spherule

Question 19

the cone is ___ microns in length

Answer 19

65-75 microns in length

Question 20

about how many rods are in the retina?

Answer 20

~ 120 million

Question 21

about how many cones are in the retina?

Answer 21

~ 6-7 million

Question 22

cone neural connection arrangement in the macula is:

Answer 22

1 cone: 1 bipolar: 1 ganglion

Question 23

the 1:1:1 ratio arrangement in the macula has what effects?

Answer 23

• increased discrimination

- decreased sensitivity

Question 24

is the outer segment of the cone shorter or longer than in rods?

Answer 24

the outer segment is shorter in cones

Question 25

is the inner segment more plump in the rods or the cones?

Answer 25

it is more plump in cones

Question 26

why is the inner segment more plump in the cones?

Answer 26

it has 4x the amount of mitochondria

Question 27

do the cones contain an outer conducting fiber?

Answer 27

no

*except in the fovea

Question 28

is the nucleus of the cell body larger in cones or rods?

Answer 28

cell body nucleus is larger in cones

Question 29

foot plate of the inner conducting fiber is called _____ in the cones

Answer 29

pedicle

Question 30

bipolar cells are a _____ neuron and located in layers _____

Answer 30

bipolar cells:

• primary neuron
• in layers 5, 6, 7

Question 31

list the 3 types of bipolar cells

Answer 31

1. rod bipolar
2. midget bipolar
3. flat bipolar

Question 32

what are the rod bipolar connections and size?

Answer 32

• connects only to rods

- large cell body and dendritic tree

Question 33

where do the midget bipolar cells have connections?

Answer 33

• involved in 1:1:1 relationship

- found in macula

Question 34

what are the flat bipolar connections?

Answer 34

• connects with several cones

- polysynaptic

Question 35

ganglion cells are a ______ neuron and found in layers ____

Answer 35

ganglion cells

• secondary neuron
• layers 7, 8, 9

Question 36

what is different about the ganglion cell layer in the macula vs. rest of retina?

Answer 36

at the macula, there are more rows of ganglion (8-10 row) but in rest of retina the ganglion cell layer is a single row

Question 37

what are the two groups of ganglion cells?

Answer 37

1. diffuse

2. monosynaptic (midget)

Question 38

what is the nerve fiber layer made of?

Answer 38

of axons from ganglion cells headed towards the optic nerve and eventually traveling to the visual cortex

Question 39

where do the the axons from the nerve fiber layer terminate?

Answer 39

in the midbrain in a structure called the lateral geniculate body

Question 40

2 types of horizontal integration cells

Answer 40

1. horizontal

2. amacrine

Question 41

where are horizontal cells located?

Answer 41

in the bipolar cell layer (INL) closest to the synapse between photoreceptors and bipolar cells

Question 42

what is the function of the the horizontal cells?

Answer 42

it is a synapse which can enhance or depress the signal between photoreceptor and bipolar cell

Question 43

what synapse can the amacrine cell enhance or depress?

Answer 43

the synapse between the bipolar and ganglion cell

Question 44

what are glial cells?

Answer 44

supportive, non-conducting cells that act like “glue”

Question 45

functions of the fibers of Mueller

Answer 45

stores glucose and structurally fills in space

Question 46

where are the Mueller cells found?

Answer 46

found in 6 layers and also contributes to ILM (layer 10) and ELM (layer 3)

Question 47

the cell body of the Mueller cell is found in what layer?

Answer 47

layer 6