The SensesHB&H Chapter 7.3

Pages 204-211

5 Senses

1. Vision2. Hearing3. Smell4. Taste5. Touch

• How do your senses work?

How Senses Work

• Each of your sense organs turns information into impulses

• Impulses are sent along neurons to your brain.

Sense of SightSense Organ: EyesStimulus: Light waves

• Light first strikes your Cornea, clear tissue that covers the front of the eye

• Light enters your eye through the Pupil.

Sense of Sight

• The Iris surrounds the pupil and control its size and how much light enters the eye– The iris also gives eyes

their color• Inside the pupil is the Lens, which focuses the light– Images in your eye are

actually upside down and reversed.

Senses of Sight

• Finally, light strikes the Retina, a layer of cells at the back of the eye

• The retina contains receptor cells called rods and cones– Rods allow you to see

shades of black, gray and white, and in dim light

– Cones see colors and work well in bright light.

1 •Cornea

2 •Retina

3 •Lens

4 •IrisThis part of the eye

covers and protects it.

1 •Pupil

2 •Retina

3 •Lens

4 •IrisThis part of the eye controls the

amount of light that enters the eye.

1 •Pupil

2 •Retina

3 •Lens

4 •Sensory NeuronThis layer of cells detects

colors.

What is Sound?

• What is sound?• How do we make sounds?

Sense of Hearing

Sense Organ: EarsStimulus: Sound waves

• Sound is produced by vibrations

• Vibrations create waves of moving particles.

Sense of Hearing

• Your ear acts like a funnel that catches sound wave vibrations

• Inside your ear is the Eardrum, a membrane that is struck by sound

• Small bones pass this on to the Cochlea.

Senses of Smell & Taste

Sense Organ: Nose & Tongue

Stimulus: Chemicals

• Work together to pick up 50 kinds of odors and 4 types of taste– Sweet, sour, salty and

bitter

Sense of Touch

Sense Organ: SkinStimulus: Pressure / Energy

• Touch lets you identify if something is rough or smooth, pressure of an object, temperature, and pain

1 •Objects

2 •Emotions

3 •Stimuli

4 •ResponseWhat are your senses

detecting?

1 •Taste

2 •Touch

3 •Smell

4 •HearingWhich of these senses detects stimuli in the form of waves?

1 •Taste

2 •Touch

3 •Smell

4 •SightWhich of these senses detects

chemical stimuli?

What to Work On

• Complete Section 7.3 Review• Answer Questions #1-4 on page 211

DUE: Friday, March 16th