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Quiz!
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receptors |
groups of specialised cells which detect changes in the environment (stimuli) and turn them into electrical impulses |
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stimuli |
changes in the environment |
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sense organs |
location of receptors; each organ has receptors responsive to different changes in the environment (to particular stimuli) |
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what are receptors in the skin sensitive to? |
touch, pressure, pain, temperature |
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what are receptors in the tongue sensitive to |
chemicals in food |
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what are receptors in the nose sensitive to? |
chemicals in the air |
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what are receptors in the ear sensitive to? |
sound and the position of the head |
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what are receptors in the eye sensitive to? |
light |
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Central Nervous System |
brain and spinal cord |
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what happens when a receptor is stimulated? |
the receptor sends an impulse along the nerve cells - neurons- to the brain. The brain coordinates a response. |
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neurons |
nerve cells |
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effector |
any part of the body that produces a response |
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give some examples of effectors |
a muscle in the arm contracting |
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name three kinds of neuron |
sensory neurons |
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sensory neurons |
carry signals from receptors to the spinal cord and the brain |
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relay neurons |
carry messages from one part of the CNS system to another |
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motor neurons |
carry signals from the CNS to effectors |
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synapse |
a tiny gap between 2 neurons. One neuron cause a chemical to diffuse across the gap causing the next neuron to emit an electrical impulse |
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reflex action |
a rapid response to a stimulus that does not involve thinking |
