BIO 2630 - Ch 15

What are the five special senses?

Vision, smell, taste, hearing, equilibrium

What makes them special senses?

They use specialized sensory receptors mainly located in the head

Main job of the eye?

Detect light and turn it into nerve signals the brain can interpret as vision

What are the 3 layers of the eyeball?

Fibrous → vascular → inner/retina

Fibrous layer contains?

Sclera + cornea

Sclera?

Tough white part that protects and shapes the eye

Cornea?

Transparent front of eye that sllows and bends incoming light

Retina?

Inner sensory layer containing the photoreceptors that detect light

Iris?

Colored portion of the eye that controls pupil size

Pupil?

Opening that allows light into the eye

Lens?

Changes shape to focus light into the retina

Basic path of light through the eye?

Cornea → aqueous humor → lens → vitreous humor → retina → photoreceptors.

What are the 2 photoreceptors?

Rods + cones

Rods are best for?

Dim light/night vision

Cones are best for?

Color + detailed vision

What is accommodation?

Changing lens shape to focus on objects?

Myopia?

Nearsightedness

Why does myopia happen?

Eyeball is too long, so light focuses in front of the retina.

Hyperopia?

Farsightedness

Why does hyperopia happen?

Eyeball is too short, so light focuses behind the retina.