2. The Nervous System Gaiser Life Science

3. Know What are the three functions of the nervous system? Evidence Page 69 The Nervous System “I don’t know any.” is not an acceptable answer. Use complete sentences. After listening to the PowerPoint lecture, come back here and list evidence to explain why your answer to the above question is or is not a good answer. You may also use other outside sources to help you respond.

4. Clarifying ?s Information Page 70 Functions 1. Receives information - inside and outside the body 2. Responds to info - reacts to stimulus (changes signal direction) Nerve cells are stimulated by pressure, pain, or other input. The stimulation becomes a stimulus that travels down the nerve axon. The message jumps the synapse from the axon terminal of one nerve cell to the dendrite of another in electro-chemical form. The message may make this jump several times on the way to the central nervous system. - another name for a nerve cell Process 3. Maintains homeostasis The Nervous System neuron - messages that travel along the nervous system impulses - branch-like structures located at the end of nerve cells, which receive electro-chemical messages from other nerve cells and carry the message to the nerve cell body or soma dendrite

5. Clarifying ?s Information Page 71 The Nervous System Examples: grasp, patellar, gag, or pupillary light reflexes to mention only a few Examples: running, opening a pop can, playing chess, or playing a piano Process (continued) The central nervous system receives the message for processing. The message can be processed in one of three ways: - a long slender projection of a nerve cell that carries the impulse away from the cell body or soma axon 1. In the case of a reflex, the message takes a short cut at the spinal column and goes back to the origin to trigger muscles. 2. Many messages go all the way to the brain to be consciously processed. - the gap between the axon terminal of one nerve cell and the dendrite of another nerve cell synapse

6. Clarifying ?s Information Page 72 The Nervous System Examples: Heart rate may increase. Breathing may become shallow. A muscle may activate an arm, leg, or hand. A gland may be stimulated to secrete a hormone. Organs can be stimulated to carry out their specific job. Process (continued) After the central nervous system determines how the message should be processed, a signal is sent back to the origin of the incoming signal. Again the message travels from one nerve cell to another. A variety of responses can then occur. Examples: heart rate, respiration rate, salivation, perspiration, and others 3. Many responses of the body cannot be consciously controlled.

7. Clarifying ?s Information Page 73 The Nervous System Divisions of the nervous system - This consists of the brain and spinal cord. It is the control center of the body. All muscles, organs, and glands are controlled from these locations. Central nervous system - these are the nerves that carry impulses from the central nervous system to all of the other locations of the body. Peripheral nervous system - a division of the peripheral nervous system that controls all voluntary actions. Somatic nervous system Examples: running, singing, swimming, walking - a division of the peripheral nervous system that controls all involuntary actions. autonomic nervous system Examples: heart rate, perspiration, respiration Summary:

9. Clarifying ?s Information The Nervous System Functions 1. Receives information - inside and outside the body 2. Responds to info - reacts to stimulus (changes signal direction) Nerve cells are stimulated by pressure, pain, or other input. The stimulation becomes a stimulus that travels down the nerve axon. The message jumps the synapse from the axon terminal of one nerve cell to the dendrite of another in electro-chemical form. The message may make this jump several times on the way to the central nervous system. - another name for a nerve cell Process 3. Maintains homeostasis neuron - messages that travel along the nervous system impulses - branch-like structures located at the end of nerve cells, which receive electro-chemical messages from other nerve cells and carry the message to the nerve cell body or soma dendrite Process (continued) The central nervous system receives the message for processing. The message can be processed in one of three ways: - a long slender projection of a nerve cell that carries the impulse away from the cell body or soma axon - the gap between the axon terminal of one nerve cell and the dendrite of another nerve cell synapse

10. Clarifying ?s Information The Nervous System Examples: grasp, patellar, gag, or pupillary light reflexes to mention only a few Examples: running, opening a pop can, playing chess, or playing a piano 1. In the case of a reflex, the message takes a short cut at the spinal column and goes back to the origin to trigger muscles. 2. Many messages go all the way to the brain to be consciously processed. Examples: Heart rate may increase. Breathing may become shallow. A muscle may activate an arm, leg, or hand. A gland may be stimulated to secrete a hormone. Organs can be stimulated to carry out their specific job. Process (continued) After the central nervous system determines how the message should be processed, a signal is sent back to the origin of the incoming signal. Again the message travels from one nerve cell to another. A variety of responses can then occur. Examples: heart rate, respiration rate, salivation, perspiration, and others 3. Many responses of the body cannot be consciously controlled.

11. Clarifying ?s Information Summary: The Nervous System Divisions of the nervous system - This consists of the brain and spinal cord. It is the control center of the body. All muscles, organs, and glands are controlled from these locations. Central nervous system - these are the nerves that carry impulses from the central nervous system to all of the other locations of the body. Peripheral nervous system - a division of the peripheral nervous system that controls all voluntary actions. Somatic nervous system Examples: running, singing, swimming, walking - a division of the peripheral nervous system that controls all involuntary actions. autonomic nervous system Examples: heart rate, perspiration, respiration

12. This PowerPoint was created from Charlene Shea’s lecture notes by Tim Paterek. It is copyrighted and may not be reproduced outside the Vancouver School District. All pictures came from Google Image Search. To fall within the Fair Use Guidelines, this PowerPoint must be used within the confines of the classroom and may not be published back onto the Internet unless the pictures are removed.