The Nervous System

... THE NERVOUS SYSTEM 1. Explain the difference between a motor and sensory nerve/neurone. Sensory neurones receive stimuli from sensory organ and receptors, which transmit the impulse to the spinal cord and the brain. Sensations transmitted by sensory neurone include heat, cold, pain, taste, smell, sight and hearing. Motor neurones conduct impulses away from the central nervous system (the brain and the spinal cord) to muscles and glands in order to stimulate them into carrying out their activities. 2. Describe how a motor impulse moves a muscle. (Include details of an action potential). When a neurone is stimulated maybe by light or sound the permeability of the cell membrane, to sodium ions, changes. Specific sodium gates or channels open and the Na ions rush into the neurone alone concentration and electrochemical gradients. This results in the potential difference across the membrane being reversed the inside becoming positive. This depolarisation lasts for approximately 1 millisecond. 3. Describe

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