5.1 - Percieving your environment

• Biologie
• Middelbare school
• vwo
• Leerjaar 2

Unit 5 Perception, behaviour and regulation

Grab your notebook and a pen

Today's lesson

- Introduction to your senses

- Which organs are we talking about?

- How do impulses start?

- How does your nervous system function?

You can sense things around you. What can you sense around you? List 5 of your senses.

Sensing things

Sensing things

You see and smell chocolate

Using sense organs

Signal (impulse) through nerves to your brain

Brain send impulse to arm muscle -> you grab the chocolate

Sense organs = zintuigen

Eyes, ears, nose, tongue, skin

Together = sensory system

Sensory organs

Sense organs send signals through the nerves to the ...

1. eyes
2. ears
3. brain
4. muscles

All your senses together form the ...

1. nervous system
2. sensory system
3. brain system
4. sense canal

How do you call the signals the sense organs send out?

Sense receptors in the skin

Heat receptors

Cold receptors

Pressure receptors 

Touch receptors

Reacting to the surrounding

Stimulus (prikkel) = information from the surrounding

Light, temperature, smell, sounds, skin contact

Stimulus -> sense organ -> impulse -> nerves -> brain 

Brain responds with a impulse to the muscles to react 

Nervous system

Central nervous system

- Brain

- Spinal cord

Nerves

Which square is darker?

Which square is darker?

Sensory cells

Sensory organs have sensory cells

Which are connected to nerves

When the sensory cells receive a stimulus they generate an impulse (kind of electrical signal)

How an impulse starts

Stimulus needs to be strong enough -> threshold value

= the lowest intensity of stimulus that causes an impulse

Example: a sound needs to be hard enough to hear 

-> Soft sounds don't cause impulses the lowest intensity of stimulus that causes an impulse

Adequate stimuli

A stimulus that sensory cells are particularly sensitive for 

Sensory cells in your eyes respond to light

Light is the adequate stimulus

Match the correct adequate stimulus to the sensory organ

Sound

Taste

Light

Smell

Non-adequate stimuli

Sometimes sensory organs will response to other stimuli

When you get hit in your eyes, you will see "stars"

But, the threshold value is higher than for the adequate stimulus

Habituation = gewenning

If a stimulus doesn't go away for a long time, your sensory cells will produce less impulses

You don't really feel your clothes on your body because of habituation

What do we call the lowest intensity that can cause an impulse?

1. Adequate stimulus
2. Threshold value
3. impulse
4. habituation

If a stimulus does not go away for some time, it starts producing less impulses in the cell. What do we call this?

1. Adequate stimulus
2. Threshold value
3. impulse
4. habituation

Fill in the right words:
The smell of a fresh panini comes into your nose, this is called a .... Then a .... is sent through the nerves to the brain.

Let's get to work

Read 6.1 in your (online) textbook

Make assignments 2, 3 and 4 in your (online) workbook