C - Senses and impulses

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• Middelbare school
• vwo
• Leerjaar 3

BS 
Senses and impulses

Sensing things

What happens over here?

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

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

1. Stimulus needs to be strong enough -> threshold value

= the lowest intensity of stimulus that causes an impulse

2. Impulse frequency - a stimulus gets stronger, more impulse per second

Adequate stimuli

A stimulus that sensory cells are particularly sensitive to, a sensory cell has a low threshold value for this stimulus 

Example: Sensory cells in your eyes respond to light

Light is the adequate stimulus

3 types of nerve cells

notes: 

1. Sensory neurons: pass the impulses from the sense organs to the CNS

2. Motor neurons: pass impulses from the CNS to the muscle/glands

3. Interneurons: conduct impulses within the CNS

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