Ch 48 - C h 48(entire chapter Neurons nerve cells that transfer information within the body t ransmit sensory info control heart rate coordinate

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Ch 48 (entire chapter) Neurons: nerve cells that transfer information within the body; transmit sensory info, control heart rate, coordinate hand and eye movement, record memories, generate dreams etc. Brain: higher order processing carried large groups of neuron organized into brain Ganglia: simple clusters nerve cell bodies in a centralized nervous system 3 stages in information processing: sensory input, integration, and motor output. Sensory neurons: transmit info from eyes and other sensors that detect external stimuli (light, sound, touch) or internal conditions (blood pressure, muscle tension) > goes to brain or ganglia - integrate the sensory input. Interneurons: vast majority of neurons in the brain which make only local connections Motor neurons: transmit signals to muscle cells, causing them to contract; relies on neurons that extend out of processing centers in bundles called nerves and generate output by triggering muscle or gland activities Central Nervous System (CNS): neurons that carry out integration includes brain and longitudinal nerve cord. Peripheral Nervous System (PNS): made up of neurons that carry into and out of the CNS; motor output Cell body: most of the neurons organelles including its nucleus are located typical Neuron has - Dendrites: highly branched extensions that receive signals from other neurons - Axon: has only one axon - extension that transmit signals
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to other cells; longer than dendrites; cone-shaped region where it joins the cell body - axon hillock, region where the signals that travel down the axon are generated; divides into several branches: > Synapse: end of an axon transmits info to another cell at a junction called synapse; the part of each axon branch that forms this specialized junction is synaptic terminal; Neurotransmitters: passes info from transmitting neuron (presynaptic cell) to receiving cell (postsynaptic cell - neuron, muscle, or gland); Glia: neurons of vertebrate reruire supporting cells; may nourish neurons, insulate the axons of neurons or regulate the extracellular fluid surrounding neurons Membrane potential: a voltage across their plasma membrane; rapid changes in membrane potential are what enable us to do what we do Resting potential: membrane potential of a resting neuron - not sending signals; -60 to -80 mV; neuron at rest negative relattive to the outside - potassium and sodium ions play a role in formation of resting potential; the concentration of potassium is higher inside the cell and lower outside. Sodium concentration is opposite; these gradients are maintained by sodium-potassium pumps uses ATP
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This note was uploaded on 01/30/2011 for the course BIOL 303 taught by Professor Birchard during the Spring '08 term at George Mason.

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Ch 48 - C h 48(entire chapter Neurons nerve cells that transfer information within the body t ransmit sensory info control heart rate coordinate

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