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SlideshowReport

A reflex arc.

Description
The knee-jerk response is an example of a reflex arc. A tap below the kneecap stretches the patellar tendon and acts as a stimulus, initiating a reflex arc that causes the extensor muscle on top of the thigh to contract. At the same time, an interneuron inhibits the motor neuron of the flexor muscle, causing it to relax.
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1 Comment
11 years ago
Great illustration, thanks for posting.
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