5.1 stimuli and responses

• Biologie
• Middelbare school
• vwo
• Leerjaar 1

What sensory organs do you know?

What senses do you know?

Senses

• Sight
• Sense of hearing
• Sense of balance
• Sense of smell
• Sense of taste
• Sense of heat/cold
• Sense of touch/pressure 

How does it work?

stimuli and responses

stimulus

sensory receptor

neurons

effectors

response

stimuli plural

stimulus

NOTICE CHANGES IN AND AROUND US

• why? to survive
• what? stimulus/stimuli
• stimulus =  external or internal change that causes a reaction

When there’s rain, the frog tends to come out because it prefers a wet environment.

stimulus => response

stimulus = external or internal change

sensory receptors = convert stimuli into electrical signals

neurons = bring these signals to your brain (impulses)

effectors = are told how to react by your brain (via impulses through neurons)  that's your response

Responding to stimuli

1. Your phone rings. The sound of the phone ringing is a stimulus.
2. Sensory receptors in your ear receive the sound and change it into nerve impulses.
   
3. The nerve impulses travel along neurons to your brain: you become aware of your phone ringing.
   
4. The brain sends its own nerve impulses along other neurons to your arm muscle.
   
5. Your arm muscle contract and you pick up the phone. Your muscles are called effectors because they make the response possible.

Impulses

Impulses = signals in nerves/ neurons

Sensory organ --impulse (neuron) --> Brain

Once the impulses reach your brain, you become aware

Brain --impulse (neuron)--> Muscles

You can move and react to the stimuli

effectors

muscles (fast response)

glands => hormones (slow response, via the blood)

1. What stimuli will your body experience in the situation described underneath?
2. How will the brains react to these stimuli?

You are using the stove, the pan has been on the stove for about 10 minutes. You touch the metal handle of the pan.

responses

voluntary => you decide to react (skeletal muscle)

involuntary => you have no control over your reaction (smooth muscle that contracts, e.g. when you'r stomach starts to growl)

Senses

involuntary responses

What now?

First 15 minutes in silence (red). Then you can whisper to your classmate next to you (orange)

• Read 118 + 119 tb
  
• Write down the difficult words + bold pressed words and make a wordlist
  
• Make exercise: 1, 2, 3
  

difficult words

1 bombarded            gebombardeerd

2 to convert                omzetten

3 specialised                  gespecialiseerd

4 destination                  bestemming 

5.2 The senses

senses

vision - light rays

hearing - sound waves

smell - chemicals

taste - chemicals

feeling (pressure, temperature, pain and touch) - heat/cold etc.

difficult words

read the paragraph and write down 3 difficult words

We will choose 5 for your notebook

five difficult words

1. detectors                             detector/sensor

2. pleasant                        nice / fijn

3. receptors                       receptor, reads a stimuli and changes it into an impulse (electrical signal)

4. corrresponding                          matching/ correspondeert/ past erbij

5. internal/external                                inside/outside