Unit 3 Workings of Mind & Body Nervous Systems Structure of Nervous System Central Nervous System part of nervous system that consists of the the brain and spinal cord What is its job : Roadway between brain and the rest of the body Peripheral Nervous System made up of nerve cells that send messages between the central nervous system and other parts of the body Back roads of central nervous system Neurons nerve cells that run through our entire body and communicate with each other (part of peripheral) Send & receive messages from other parts of the body, such as muscles and glands. Messages relate to events like a pinch or a memory Neurons are individual cells, nerves are a large collection of nerve fibers What makes up a Neuron? Cell body produces energy that fuels the neurons activity Dendrites branch out from the cell body. They receive information from other neurons and pass message through cell body. Many Axon transmits information away from the cell body Only one Myelin fatty substance that protects the axon Synapse junction between axon terminals of one neuron & the dendrites of another. Messages only go forward Types of Neurons Neurons are classified by the direction in which they carry information Sensory send information from the sensory receptors (eyes, ears, nose, mouth) TO the central nervous system Motor Take information AWAY from the central nervous system and carry it TO muscles and glands. Interneurons Carry information between sensory neurons and motor neurons Most are located in the central nervous system What is a Neurotransmitter? Neurotransmitters are chemicals that are stored in sacs in the axon. How does it work? A neuron fires (sends message) by releasing neurotransmitters. Each message is converted into a electrical impulse that travels. The message is then forwarded to the next neuron by other neurotransmitters, until it reaches its destination. What happens if neurotransmitters are misfiring? Can cause some diseases or psychological disorders For example, deficiency in neurotransmitter dopamine plays a role in Parkinson's disease. (not enough dopamine) Hallucinations and hand shaking Too much dopamine, may contribute to Schizophrenia Hallucinations and illusions Neuronsthe video moEmoE Nervous System Break Down SystemFunctionDetails Central Nervous System C.N.S. Made up of the brain and spinal cord. Transmits messages between the brain and the muscles & glands in the body. Brain depends on spinal cord to send the message Peripheral Nervous SystemLies outside the C.N.S. & Is responsible for transmitting messages between the C.N.S. & rest of body Split into the Autonomic & Somatic Nervous System Autonomic Nervous System Regulates bodys vital functions that dont require thought: heartbeat, breathing etc. Helps your body prepare for stressful situations like fight or flight. Somatic Nervous SystemTransmits sensory messages to the C.N.S. Carry messages from the voluntary muscles & sense organs Activated by touch, pain, changes in temperature etc. Central Nervous SystemPeripheral Nervous System Autonomic Nervous SystemSomatic Nervous System Fight or Flight Response Video How do our bodies react to fear? What is adrenaline? Have you ever heard of an adrenaline rush? What is it? Can adrenaline make you do extra ordinary things? Reaction Lab Exit Ticket Page 71 of text book Answer numbers 1-4