Chap 3 lecture notes NO PPT

Chap 3 lecture notes NO PPT - Chapter 3 All human behavior...

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Chapter 3 All human behavior depends on rapid information travel and processing…the nervous system is the body’s communication network, handling information just as the circulatory system handles blood It operates using an electrochemical communication system Communication within this system forms the basis of ALL thought, feeling, and behavior We will start by reviewing the smallest most microscopic components of this system and then build to more complex levels of organization The basic components of the nervous system are living cells called neurons and glial cells Neurons Neurons – cells in the nervous system that communicate with one another to perform information-processing tasks. They receive, integrate, and transmit information 1. Approximately 100 billion neurons in the brain 2. Neurons produce the underlying invisible physical component of visible behavior 3. Neurons came in many shapes and sizes, and they communicate without touching Components of the Neuron: 3 Basic Parts 1. Dendrites – receive information from other neurons and relay it to the cell body. Word derived from Greek word for “tree”. Dendrites often resemble branches of a tree 2. Cell Body (Soma) – coordinates the information-processing tasks and keeps the cell alive. Integrates information 3. Axon – transmits information to other neurons, muscles, or glands. Like the cable from your computer to your printer carrying signal to print. Many dendrites, but only one axon. Myelin Sheath – an insulating layer of fatty material around the axon that speeds conduction. Multiple sclerosis is a myelin degeneration disease, causing loss of muscle control, etc. due to loss of transmission efficiency in the nervous system when the myelin sheaths deteriorate. The myelin sheath is composed of glial cells Glial Cells – support cells found in the nervous system. There are 10 to 50 times more glial cells than neurons. Glial cells clean up dead tissue, provide nutrients to neurons, and provide myelin for axons. They also hold the neurons in place as structural support. Synapse – the junction between one neuron’s axon and another neuron’s dendrite or soma. Each neuron may be connected to thousands of others via synapses. Adults have between 1
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100 and 500 trillion synapses. Major Types of Neurons- ONLY NEED TO KNOW SENSORY AND MOTOR Sensory neurons – receive information from the external world and convey this information to the brain via the spinal cord Motor neurons – carry signals from the spinal cord to the muscles to produce movement Interneurons – connect sensory neurons, motor neurons, and other interneurons Electrical Signaling: Communicating Information within a Neuron Communication within and between neurons proceeds in two stages - conduction and transmission , together referred to as electrochemical action 1. First the a signal is received and may initiate electrical conduction down the axon 2. Second, the signal travels chemically across the synapse to the next neuron via
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Chap 3 lecture notes NO PPT - Chapter 3 All human behavior...

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