Week 6 key terms Flashcards
What is a retina?
The light sensitive part of the eye
what is the retina made up of? (2)
photoreceptors
Layers of neurons on the top
What neurons is the retina made up of? (4)
- ganglion cells
Horizontal
Bipolar
Amacrine
What is the fovea?
The central potion of the retina
what is the fovea packed of?
photoreceptors
What is the lens?
A structure in the eye that helps focus an image on the retina
What are the main terms for vision problems? (3)
The hypermetropic eye
The myopic eye
The presbyopic eye
What is a hypermetropic eye?
Long sighted vision- lens does not bend enough
what is a myopic eye?
short-sighted eye- lens bends too much
what is a presbyopic eye?
Lens no longer flexible enough to focus clearly
What are ohotoreceptors?
Retinal receptors that convert might into neural activity
What are cones?
Photoreceptor’s that respond to colour and bright lights
what are rods?
photoreceptors that respond to dim light and Black and white
What are bipolar cells?
A retinal neuron that uas 2 different types of receptive fields that each respond differently to light
What are the 2 receptive fields in the bipolar fell?
- on-centre
- off-centre
What is an on-centre receptive field?
When light hits the eye, less glutamate is received exciting the cell
What is an off-field receptive field?
When light id turned off, more glutamate is received exciting the cell
What are the 2 different types of cells in the Retinal ganglia?
Magnocellular cells (M-cells) Parvocellular cells (P-cells)
What are magnocellular cells sensitive to? (3)
Where do they get info from?
Sensitive to light not colour
Sensitive to movement and low contrast not colour and fine detail
where are magnocellular cells present in the eye?
Present throughout retina and periphery