Development of Visual Pathway Flashcards Preview

Human Development > Development of Visual Pathway > Flashcards

Flashcards in Development of Visual Pathway Deck (20):
1

At what week does the visual system begin to develop?

3 weeks

2

What embryological tissue gives rise to the retina, the fibers of the optic nerve and smooth muscle of the iris?

Neuroectoderm

3

What embrylogical tissue forms the corneal and conj. epithelium, the lens and the lacrimal and tarsal glands?

Surface ectoderm

4

What embryological tissue forms the corneal stroma, sclera, choroid, iris, ciliary muscle, vitreous body and the cells lining the anterior chamber?

Mesenchyme

5

What part of the brain does the eye develop from?

Forebrain (specifically diencephalon)

6

Around what embryo day does the retina begin to develop?

30 days

7

Around what embryo day does the LGN begin to develop?

36 days

8

Around what embryo day does the cortex begin to develop?

40 days

9

People who become blind early tend to have a thicker visual cortex due to the failure of what?

Failure of pruning and retraction of processes

10

Initial steps of cell generation are under what 2 types of control?

Chemical or molecular control

11

Once synaptic connections are made between the cells, development is more influenced by what?

Electrical activity between the cells in the system

12

What retinal cells develop first?

1. Ganglion
2. Horizontal
3. Amacrine cells
4. Cone cells

13

What retinal cells develop second?

1. Rods
2. Bipolar cells
3. Mueller glial cels

14

T/F: The central part of the retina is generated first and the peripheral parts later.

True

15

What guids the axons of ganglion cells to the optic nerve head?

Proteins

16

If an animal is kept in the dark, will the segregation of on-off responses of ganglion cells develop?

No

17

If the electrical responses are blocked, will the segregation of on-off responses of ganglion cells develop?

No

18

What guides the nasal retina nerve fiber axons into, through and out of the chiasm ?

Slits - extracellular matrix molecules

19

What affects the guidance facts expressed by retinal ganglin cells in Albinos?

the lack of melanin in the pigment epithelium in the retina

20

In albinos, some of the temporal half of the retina project abnormally tot he contralateral LGN. What does this cause in the patient?

Lack of binocular coordination between the 2 images/eyes