Visual system

Question 1

What is the outer layer in the eye called?

Answer 1

sclera - continuous dural sheath of optic nerve

Question 2

what is the Uvea made up of and what is a property of this layer?

Answer 2

outer choroid, inner ciliary body and iris

pigmented and vascular layer

Question 3

what are the layers of the retina from superficial to deep?

Answer 3

Retinal pigment epithelium 
photoreceptor cells 
bipolar cells
ganglion cell layer
nerve fibre layer

Question 4

why is retinal epithelium pigmented ?

Answer 4

to prevent light bouncing so to stop glare

Question 5

What are bipolar cells in the nervous system and how do they achieve lateral inhibition ?

Answer 5

first order neurones

connected via horizontal cells to enhance edges

Question 6

What receives input from bipolar cells?

Answer 6

ganglion cells

Question 7

where does the macula sit from the optic disc?

Answer 7

lateral

Question 8

what is amaurosis fugax ?

Answer 8

sudden visual loss due to occlusion of central retinal artery

Question 9

What is used to view the layers of the retina?

Answer 9

OCT- Optical coherence tomography

Question 10

what is the medial retina referred to ?

Answer 10

nasal retina

Question 11

what is the lateral retina referred to ?

Answer 11

temporal

Question 12

What does the optic tract project ?

Answer 12

ganglion cells axons to the lateral genticulate nucleus in the thalamus

Question 13

what do the optic radiations project?

Answer 13

lateral genticulate to visual cortex

Question 14

what is a scatoma?

Answer 14

localised defect in to retina causing a small patch of visual loss

Question 15

how do you name which side the lesion is on?

Answer 15

the side with the lateral visual loss

Question 16

how do you get macula degeneration ?

Answer 16

non-vascular damage to occipital lobe

Question 17

how can you get macular sparing visual loss?

Answer 17

occlusion of the posterior cerebral artery.

Question 18

Where do the superior radiations project to ?

Answer 18

the parietal lobe

Question 19

where do the inferior radiations project to ?

Answer 19

temporal lobe

Question 20

Why is there a consensual reflex?

Answer 20

the pretectal nucleus projects bilaterally to EDW nuclei

Question 21

What is the accommodation reflex?

Answer 21

Pupil constriction, convergence of eyes and thickening of lens

Question 22

What is the processing centre for the accommodation relfex?

Answer 22

Visual cortex via lateral geniculate nucleus to oculomotor and edinger westphal nucleus