Lesson 1: The nervous system

• Biologie
• Middelbare school
• vwo
• Leerjaar 2

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Brain and Senses

Lesson 1: Neurons and the brain

How do you detect and respond to changes? 

• Nervous system: electrical messages
• Hormonal system: chemical messages

Getting a reaction

-Stimuli (a change that can be detected)

-Receptors (detect changes)

-Effectors (bring about a response)

An example 

Throwing a pen towards someone 

• Stimuli --> the pen coming towards you 
• Receptors --> retina of your eye 'seeing' the pen 
• Effectors --> muscles in your arm to catch the pen

The Nervous system

The nervous system controls your muscles 

-walk / write / exercise 

-swallowing / blinking / breathing

-Central nervous system vs. 

-Peripheral nervous system

The central nervous system (CNS)

Nerve cells / neurons 

• Sense organs (receptors) send messages to the CNS

via Sensory neurons

• Muscles and glands (effectors) CNS send messages telling them wat to do 

via Motor neurons

The message

-Nerve impulses (electrical signals)

-Via the axon of the nerve cell

-Fatty sheat around axons make the impuls travel faster

-Multiple slerosis (MS) the fatty sheat breaks down they lose their use of the muscles 

Reflex (en reflexboog)

Reflexboog

Reflex

You get an itch in your elbow. What is the stimulus in this reaction?

1. Receptors in your skin
2. The itch itself
3. muscles that move your arm to scratch
4. The brain that decides to scratch the elbow

You get an itch in your elbow. What is the response in this reaction?

1. Receptors in your skin
2. The itch itself
3. muscles that move your arm to scratch
4. The brain that decides to scratch the elbow

You get an itch in your elbow. What is the coordinator in this reaction?

1. Receptors in your skin
2. The itch itself
3. muscles that move your arm to scratch
4. The brain that decides to scratch the elbow

You get an itch in your elbow. What is the receptor in this reaction?

1. Receptors in your skin
2. The itch itself
3. muscles that move your arm to scratch
4. The brain that decides to scratch the elbow

Which will send a message along sensory neurons?

1. Receptors in your skin
2. The spinal cord
3. The muscles in your arm
4. The brain

Which will receive a message by motor neurons?

1. Receptors in your skin
2. The spinal cord
3. The muscles in your arm
4. The brain