Chapter: 3 Movement in & out of Cells

Each eye is set in a bony socket in the skull, which protects the eye.

• Each eye is set in a bony socket in the skull, which protects the eye.
• Only the very front of the eye is not surrounded by bone. The eye is filled with fluid, which helps to keep it in shape.

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The retina

• The retina is at the back of the eye.
• This is where the receptor cells are. when light falls on a receptor cell in the retina, the cell sends an electrical impulse along the optic nerve to the brain.
• The brain uses the impulses from each receptor cell to build up an image.
• Some of these receptor cells are sensitive to light of different colors, enabling us to see colored images.
• There are no receptor cell where the optic nerve leaves the retina.
• This part is called the blind spot.
• If light falls on this place, no impulses will be sent to the brain

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