| What is the Nervous System made up of? | It has a lot of Nerve Cells, also known as Neurones which goes to all the parts of your body |
| What are sensory receptors? Any types? | This is receptors that can see a Stimulus [Change of the Environment] There are:
Eyes Stimulus that detects Light
Skin Receptors that detect Touch and Temperature. |
| When a Stimulus detects a change in the environment, what happens? | The Stimulus sends the Information it got, as a Nervous Impulses [Electrical Impulses.] This impulse is Carried along Sensory Neurones to the Central Nervous System [CNS] |
| Where and what is the CNS? | The CNS is simply the Brain and Spinal Cord working together. They decided what the Response should be, and sends the Decision along a Motor Neurone to a Effector |
| What is, and can an Effector do? | It is a Muscle, or a Gland. It can Contract, or release a hormone. This is dependent on what the situation is, and the Response by the Brain |
| Example. Your hand is feeling a smooth wall. Explain what happens in terms of the Nervous System. | -Your Receptor feels a Change in the Environment [Hits a wall] and decides to Send the Information.
-This Information is sent through a Sensory Neuron, and it reaches the CNS
-The CNS takes it to the Brain for it to make a Response. [Conscious Thought is Present, Your are thinking about it]
-The Response is taken through a Motor Neuron, to an Effector that can either Back away from the wall, or Leave it there. |
| So how are the Electrical Impulses Carried in an Neuron? | They are passed via the Axon of the Neuron. |
| Whats at the Ends of the Neurons? | They have Long Endings that Split up [Dendrites] This can connect with Other Neurons |
| What are the Axons surrounded by? | They are coated with Myelin, which is Fatty Sheath. This behaves as an Electrical Insulator, which can Speed up the Electrical Impulse. |
| Why are the Neurons long? What is the Connection called? | They are long, so that they can Speed up the Impulse. When you connect with another Neuron, it takes more Time.
The connection is called a Synapse. |
| Explain how the Impulse goes through the Synapse | The Impulse starts the release of Transmitter Chemicals, which can Diffuse across the Synapse.
They connect on to the Receptor Molecules, that are located in the Membrane of the Next Neuron. This then starts off a New Electrical Impulse. |
| What is special about Reflex Actions | They are actions that happen automatically, and don't need the Brain Involved. This makes it more Quicker than the Normal
Responses.
Instead of going to the Brain, it just goes through a Relay Neuron, found in the Outskirts of the CNS, or a Unconscious bit of the Brain. |
| So what happens in an Reflex Action | So, the Sensory Neuron goes through a Relay Neuron, instead of bringing it up for Though Time. The Relay Neuron is conveniently next to a Motor Neuron, so the 'Response' is sent very quickly. |
| Example: Your hand touches a Hot Pan. What happens in terms of the Reflex Actions. | The Skin Receptor sees that Change in the Environment [Stimulus] and sends the Information along a Sensory Neuron
The Message is reached to the Outskirts of the CNS, where a Relay Neuron grabs hold of it
The Relay Neuron gives it to the Motor Neuron, which delievers it to an appropriate muscle, for it to Contract in this case, because its not really a good thing |
