Reflex Responses

Your conscious brain can decide how to respond to a stimulus pretty quickly. But sometimes waiting for the conscious part of your brain to make a descion is just too slow. That’s why you have reflexes.

Reflex Responses are Automatic and FAST

• Voluntary responses the things you decide to do can be quick. The conscious part of your brian can process information and make decisions quickly, and electrical impulses travel fast along neurones.
• But sometimes that’s not quick enough. Reflex or involuntary responses are quicker then voluntary responses because you don’t think about them. Reflex responses are automatic and unconscious.
• Reflex actions are there to save your body from injury for example by pulling your hand off a hot object quicker than you could if you had to think about it.

A Reflex Arc Goes Through The Central Nervous System

• The neurones in many reflex arcs go through the spinal cord or through an unconscious part from the brain .
• When a stimulus for example a painful bee sting is detected by receptors an impulse is sent along a sensory neurone to the CNS.
• In the CNS the sensory neurone passes on the message to another type of neurone a relay neurone.
• The relay neurone relays the impulse to a motor neurone.
• The impulse then travels along the motor neurone to the effector a muscle in this example.
• The muscle then contracts and moves your hand away from the bee.
• Because you don’t have to think about the the response which takes time it’s quicker than normal responses.