Lecture 1/4 Flashcards Preview

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Flashcards in Lecture 1/4 Deck (47)
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1
Q

rods are ___ microns in length

A

100 microns

2
Q

are rods shorter or longer than cones?

A

rods are longer than cones

3
Q

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

A

10 rods: 5 bipolar : 1 ganglion

4
Q

funnel shape arrangement of the rod wiring has what effects?

A
  • decreased discrimination

- increased sensitivity

5
Q

outer segment of photoreceptor is ___ microns in length

A

25 microns in length

about 1/4 the total length

6
Q

photopigment in rod outer segment is:

A

rhodopsin

7
Q

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

A

700-1000 discs piled up

8
Q

the function of the inner segment of the photoreceptors is:

A

for metabolism

9
Q

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

A

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

10
Q

the inner segment is made up of what 2 components?

A
  • ellipsoid

- myoid

11
Q

what does the ellipsoid of the inner segment contain?

A

high concentration of mitochondria (for energy)

12
Q

what does the myoid of the inner segment contain?

A

vesicles containing endoplasmic reticulum, golgi apparatus, and ribosomes

13
Q

what is the purpose of the outer conducting fiber?

A

connects inner segment to the cell body

14
Q

nucleus of the rod is ___ microns

A

5 microns

15
Q

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

A

the nucleus of the rod is smaller

16
Q

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

A

the nucleus of the rod is farther away from the ELM

17
Q

purpose of the inner conducting fiber:

A

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

18
Q

foot plate in the rods is called _____

A

Spherule

19
Q

the cone is ___ microns in length

A

65-75 microns in length

20
Q

about how many rods are in the retina?

A

~ 120 million

21
Q

about how many cones are in the retina?

A

~ 6-7 million

22
Q

cone neural connection arrangement in the macula is:

A

1 cone: 1 bipolar: 1 ganglion

23
Q

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

A
  • increased discrimination

- decreased sensitivity

24
Q

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

A

the outer segment is shorter in cones

25
Q

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

A

it is more plump in cones

26
Q

why is the inner segment more plump in the cones?

A

it has 4x the amount of mitochondria

27
Q

do the cones contain an outer conducting fiber?

A

no

*except in the fovea

28
Q

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

A

cell body nucleus is larger in cones

29
Q

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

A

pedicle

30
Q

bipolar cells are a _____ neuron and located in layers _____

A

bipolar cells:

  • primary neuron
  • in layers 5, 6, 7
31
Q

list the 3 types of bipolar cells

A
  1. rod bipolar
  2. midget bipolar
  3. flat bipolar
32
Q

what are the rod bipolar connections and size?

A
  • connects only to rods

- large cell body and dendritic tree

33
Q

where do the midget bipolar cells have connections?

A
  • involved in 1:1:1 relationship

- found in macula

34
Q

what are the flat bipolar connections?

A
  • connects with several cones

- polysynaptic

35
Q

ganglion cells are a ______ neuron and found in layers ____

A

ganglion cells

  • secondary neuron
  • layers 7, 8, 9
36
Q

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

A

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

37
Q

what are the two groups of ganglion cells?

A
  1. diffuse

2. monosynaptic (midget)

38
Q

what is the nerve fiber layer made of?

A

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

39
Q

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

A

in the midbrain in a structure called the lateral geniculate body

40
Q

2 types of horizontal integration cells

A
  1. horizontal

2. amacrine

41
Q

where are horizontal cells located?

A

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

42
Q

what is the function of the the horizontal cells?

A

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

43
Q

what synapse can the amacrine cell enhance or depress?

A

the synapse between the bipolar and ganglion cell

44
Q

what are glial cells?

A

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

45
Q

functions of the fibers of Mueller

A

stores glucose and structurally fills in space

46
Q

where are the Mueller cells found?

A

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

47
Q

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

A

layer 6