5.1 - Percieving your environment

• Biologie
• Middelbare school
• vwo
• Leerjaar 2

Unit 5 Perception, behaviour and regulation

Grab your notebook and a pen

Everybody gets one.

Describe this vegetable to your neighbour. (2 min)

Today's lesson

- Introduction to your senses

- Which organs are we talking about?

- How do impulses start?

- How does your nervous system function?

Learning objectives

5.1.1 You can describe how the senses work.

5.1.2 You are able to list the senses along with their locations and their stimuli.

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

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 

Sensing things

• Sense organ: an organ that is sensitive to stimuli.
• Stimulus:  information from the surroundings that has an effect on an organism.

Come up with three examples. (1 min)

Sensing things

You see and smell chocolate.

Your sense organs send a signal (impulse) through your nerve to your brain.

Sensing things

Your brain sends impulse to your arm muscle -> you grab the chocolate. 

Responding to our environment. 

Put these concepts in the right order.

Stimulus

Sense organ

Impulse

Nerve

Brain

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

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 loud enough to hear 

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

Non-adequate stimuli

Sometimes sensory organs will respond 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: they will make the threshold value higher!

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

Which square is darker?

Which square is darker?

Sense organs = zintuigen

Eyes, ears, nose, tongue, skin

Together = sensory system

All sensory organs together = sensory system

Nervous system

Central nervous system

- Brain

- Spinal cord

Nerves

Sense receptors in the skin

Heat receptors

Cold receptors

Pressure receptors 

Touch receptors

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

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

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.

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)

Get to work

Three minutes in silence: 

• Answer the questions from the beginning.
• Write down any questions you still have.

After the timer has gone off

• Discuss your answers and questions in small groups. 

Homework

Read 5.1 in your book and watch video (link on Magister)

Do assignment 10 (Synasthesia)

When finished:

Task 19 and 20: assignments 5.1 (1, 2, 3, 5, 7 and 9)