Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Neural Biology 1 > retina- layering, RPE, glial cells and vasculature > Flashcards

retina- layering, RPE, glial cells and vasculature Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

What are vegetative structures?

A

optical components- lens cornea and supportive tissues such as the choroid, ciliary body, sclera and iris

  • these structures serve to ensure we have a good image on a heathy reitna
  • retina most important
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is transduction?

A

the photoreceptors of the retina convert the optical image into neurobiological activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the signal from transduction processed by?

A

the retina and leaves the eye via the optic nerve as a series of nerve impulses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the retina?

A

-a thin sheet of nerve and glial cells which line the inside posterior globe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the retina anteriorly?

A

-anteriorly it terminates at the ora Serrata - ora Serrata is at the uneven boundary-between retina and ciliary body- it is where the retina and chord stop and ciliary body begin -anteriorly.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What about the retina posteriorly?

A

posteriorly it’s bounded by the choroid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the choroid?

A
  • middle layer of the posterior eye
  • vascular layer
  • responsible for nutrient supply to the outer retina
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the inner boundary of the retina?

A

vitreous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the outer boundary of the retina?

A

choroid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is a layer inside the choroid?

A

retinal pigment epithelium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the 10 layers of the retina?

A
  1. retinal pigment epithelium
  2. rod and cone (photoreceptor) layer.
  3. External limiting membrane
  4. Outer nuclear layer
  5. Outer plexiform layer
  6. Inner nuclear layer
  7. Inner plexiform layer
  8. Ganglion cell layer
  9. Nerve fibre layer
  10. Internal limiting membrane
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the outermost retina layer?

A

-single layer of heaxagonal epithelial cells- retinal pigment epithelium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the neural retina?

A
  • rest of the 9 layers internal to the retinal pigment epithelium
  • made up of 6 types of nerve cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Why are there 3 , 4 , 5 layers in the retina?

A

they are there due to the photoreceptors (rods and cones) - those cells convert light energy into a neurobiological activity
-These cells are partly responsible for the rod and cone layer and the nuclei make up the outer nuclear layer and the synapses are here in the outer plexiform layer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is attached to the photoreceptors?

A

Bipolar cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are bipolar cells in the retina?

A
  • send dendrites up to photoreceptors and axon down into the inner retina
  • their nuclei make up the inner nuclear layer (6)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is internal to that?

A

Ganglion cells-

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the 3 cell types that run vertically through the retina?

A
  1. Photoreceptors
  2. Bipolar cells
  3. Ganglion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the 2 cell types that run horizontally through retina?

A
  • horizontal cells- outer retina

- amacrine cells- inner retina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What do the ganglion cell axons make up?

A

the nerve fibre layer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Where do the ganglion cells lead to?

A

all run towards the optic disc and puncture through the sclera and leave the eye as the optic nerve which connects the ey to the rest of the brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What can you use to see the retina?

A

OCT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Where is the choroid?

A

top or bottom depending on the book

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the structure of the retinal pigment epithelium?

A
  • simple squamous or cuboidal epithelium which lies between neural retina and choroid
  • separate by the choroid by Bruch’s membrane
  • cells are hexagonal in shape
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What are the cells like centrally in RPE?

A

10 across x 14um tall

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are the cells like in the periphery near the ora serata?

A

can be wider e.g 60um wide against 14um tall

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What do the central cells have in RPE?

A

One nucleus at base of the cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What do the periphery CELLS have in RPE?

A

may have several nuclei

29
Q

What is RPE like?

A

largely amitotic- lose with age

30
Q

What happens if retinal cells die and are not replaced during age?

A

the cells that surround the dead cells will just migrate to take their place
-retinal pigment epithelial cells will get more irregular in outline as we age.

31
Q

What are the cells joined as in RPE?

A
  • Very tightly joined together
  • Neighbouring cells are joined by occluding junctions (which don’t let substances between the cells)
  • There are also some adhering junctions and desmosomes
32
Q

Why arE there occluding junctions IN THE retina?

A

-to make sure no substances get from the choroid into the retina between the pigment epithelial cells

33
Q

What happens if a substance wants to get to retina?

A
  • if a substance wants to get from the blood vessels in the choroid into the nerual retina , it cant go between the cells, has to go through the cells.
  • So the cells of the RPE , can control what goes into the reitna- form part of the blood-retinal barrier
34
Q

What does the tangenital section show of RPE?

A
  • the hexagonal shape of the cells

-

35
Q

What are the RPE contains?

A
  • packed full of pigment -

- melanain granules

36
Q

What do you see in cell nearest to choroid?

A

-RPE have lots of villi - folding - 1um in size

37
Q

What do the Villi/’ foldings do in the choroidal surface?

A

-this is to increase the SA- as nutrients have to get into the RPE and ultimately to the retina

38
Q

What about the surface of the RPE nearest to photoreceptor of retina?

A

sends down much longer finger-like extension

  • 7-10um long
  • part of photoreceptors which are known as outer segments
39
Q

What are the functions of the extensions coming down from the RPE?

A

-envelop the photoreceptors -

40
Q

What are the 2 surfaces of RPE that have extensions on them?

A
  • nearest to the choroid- small extension - increase surface area
  • nearest to retina - long extension to anchor the outer parts of the photoreceptor
41
Q

What is the funciton of the RPE?

A
  • To reduce stray light by absorbing light not absorbed by the photoreceptors
  • The effect of being filled sith melanin is part of the eyes black box effect which means it stops stray light stimulating photoreceptors (which is good as we don’t want that)
  • melanin is there to absorb the stray light
  • Ingests dead bits of photoreceptors and destroys them- Phagocytosis
  • Helps to maintain blood retinal barrier
  • Storage of vitamin A - important for visual pigment regeneration (for photoreceptors)
42
Q

What does the posterior surface of the iris have?

A

melanin

  • to ensure light hitting iris doesnt get into the eye
  • absorb stray light bouncing in the eye
43
Q

What other structures contain melanin in the eye?

A
  • the outer epithelium of the pars plicata and pars plana of the ciliary body
  • At the ora serrata the pigmented epithelium of the pars plana continues as the RPE
44
Q

What does melanin do?

A

black-box effect

45
Q

What are the spaces/seperation between photoreceptors in the outer retina?

A

fluid-like substance - Interphotoreceptor matrix

46
Q

What is in the interphotoreceptor matrix?

A

proteins
glycoproteins
-acts as glue and helps glue the photoreceptors to the RPE

47
Q

Where are there no junctions?

A

between photoreceptors and RPE

48
Q

What are the gaps in the other retinal layers filled by?

A

glial cells (non-neural cells)

49
Q

What are the 3 types of glial cells in the retina?

A
  • Astrocytes
  • Perivascular glia
  • Microglia
  • Muller cells
50
Q

Where do the 3 types of glial cells occur in the retina?

A

occur in the inner layers of the retina

51
Q

What is the most important type of glial cell?

A

Muller

52
Q

What is the muller cell do ?

A

makes up the bulk of retina with volume and weight

53
Q

What do the muller cells form?

A

fibre baskets around base of photoreceptors inner segment

54
Q

What do the muller cells do in the retina?

A

in the nuclear layer, within that layer, you also have nuclei of Muller cells, and send process inwards and end feet of Muller cells form the internal limiting membrane
-going the other way from the cell body and go all the way up to the external limiting membrane, font go all the way to the retina, stop at the external limiting membrane.

55
Q

What are the functions of the muller cells?

A
  • space fillers
  • electrical insulators- work like myelin- they electrically insulate adjacent cells
  • nutritive- stuffed with glycogen granules- supplies nutrients to the retina
  • electrophysiological function
  • Involved in the regeneration of cone visual pigments
  • light guides
56
Q

What is the blood supply for retina:?

A

-have a dual retinal supply- meaning getting blood supply from 2 different places

57
Q

What does the outer retina recieved its nutrients from?

A

they are without blood vessels and received their nutrients from the choriocapillaris

58
Q

What is in the inner five layers of retina?

A

have their own blood supply coming from the central retinal artery

59
Q

What forms the central retinal artery?

A
  • a branch of the opthalmic artery enters the optic nerve and forms the central retinal artery
  • comes of and punctures the optic nerve and through the optic disc to reach the inner 5 layers of the retina
  • This runs to the surface of the optic disc
60
Q

What is the fundus image showing?

A

emanating from the centre of optic disc have these branches of the central retinal artery.

61
Q

What happens when entering the retina ?

A

the central retinal artery divides into 4 main branches

  • superior temporal
  • superior nasal
  • inferior nasal
  • inferor temporal
62
Q

How does the blood vessel divide into 4?

A

one blood vessel comes into retina through the optic nerve and when it reaches the surface of the retina it divides into 4 to supply the 4 quadrants of the eye

63
Q

What do the nerve fibres do in retina?

A

branches of the central retinal arteries running in the nerve fibre layers.

  • They then supply the inner five layers of the retina by sending down capillaries to the middle of the retina
  • have densely networked of capillaries s throughout the inner 5 layers of the retina
64
Q

What is the tangential section of retina?

A

shows a dense network of capillaries

-parallel to the surface of the retina

65
Q

What happens within the retina with arteries ?

A
66
Q

What are veins like?

A

thin walls making them appear darker than arteries

67
Q

What happens when looking at fundus?

A
  • arteries are thinner and lighter

- veins are thicker and darker

68
Q

How many people have vessels that arise from choroid and enters there retina near the optic nerve head?

A

25% of people

can supply nutrients to retina
known as a cilioretinal artery

Neural Biology 1 (58 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions