The Nervous System and Responding to Stimuli.

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Coordination and Response

The Nervous System and Responding to stimuli

Organism need to respond to their environment to survive:

Receptors and Effectors

  • Receptors detect stimuli; these receptors are found in sense organs like eyes and ears for example cone cells in the eyes detect light change.
  • Effectors are the cells that bring about a response from the stimuli such as the muscle cells and hormonal gland cells.
  • They communicate using the nervous and hormone systems.

The Central Nervous System  (CNS)

Your nervous system is made up of sensory, motor and relay neurones.

The CNS is your Spinal cord and Brain only.

When the receptors in a sense organ detect a stimulus then electrical impulses through sensory neurones are sent.

The CNS then sends electrical impulses to an effector using a motor neurone.

The CNS ‘s job is to coordinate the response and because it uses electrical impulses it is very rapid.

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Reflexes are automatic and un ordered responses that your body does to minimise damage to your body. It can do it through CNS  or Hormones. The Path the message takes is the REFLEX ARC.

It goes:

The Reflex Arc goes through the Central Nervous System

A stimuli makes a receptor active, then it sends an electrical signal through sensory neurones to the spinal cord. Then it is passed onto another neurone called the relay neurone. Between the neurones there are gaps called synapse. The message is chemically passed between these. From the relay neurone the impulse gets ...

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