The Senses & Vision

p. 614

1. What are the five senses?

1. Vision

2. Hearing

3. Smell

4. Taste

5. Touch

2. What is the overall function of the senses?• Pick up specific information about the

environment.

3. How do the senses work?

• They each change information to nerve impulses and send those impulses to the brain.

4. How do eyes enable people to see?• Eyes respond to the stimulus of light.

• They convert this stimulus to nerve impulses that your brain interprets.

light nerve impulses

5. What are the structures of the eye?

Vitreous HumorLens

Sclera

Pupil

Cornea

Iris

retina

Optic Nerve

5. What are the functions of the structures of the eye?

• Cornea – clear tissue that covers the front of the eye

Vitreous HumorLens

Sclera

Pupil

Cornea

Iris

retina

Optic Nerve

• Pupil – opening through which light enters the eye; appears as a dark circle.

Vitreous HumorLens

Sclera

Pupil

Cornea

Iris

retina

Optic Nerve

• Iris –surrounds pupil and regulates the amount of light entering the eye.

• Gives eye its color (blue, brown, green, etc)

Vitreous HumorLens

Sclera

Pupil

Cornea

Iris

retina

Optic Nerve

• Sclera – tough, thick, white, outer covering of the eye.

Vitreous HumorLens

Sclera

Pupil

Cornea

Iris

retina

Optic Nerve

• Vitreous humor – thick, transparent jelly-like fluid.

Vitreous humor

Vitreous HumorLens

Sclera

Pupil

Cornea

Iris

retina

Optic Nerve

Vitreous HumorLens

Sclera

Pupil

Cornea

Iris

retina

Optic Nerve

• Retina – layer of light sensitive cells that detect the image.

• Optic nerve – bundle of nerve fibers that carry information from the retina to the brain.

Vitreous HumorLens

Sclera

Pupil

Cornea

Iris

retina

Optic Nerve

• Lens – clear and flexible; focuses light.

Vitreous HumorLens

Sclera

Pupil

Cornea

Iris

retina

Optic Nerve

6. What are the 2 types of receptor cells in the retina?• Rod cells:

– work in dim light – enable you to see

black, white, and shades of grey.

• Cone cells: – work in bright light– enable you to see

colors.

7. How does the lens affect the light?• The lens bends the light rays, and

produces an upside down and reversed image.