Neurons - receptive surface that receives information from...

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Neurons: Structural units of the nervous system. Highly specialized cells that conduct messages in the form of nerve impulses from one part of the body to another. They have extreme longevity. Neurons are amitotic. High metabolic rate; require continuously abundant supplies of oxygen and glucose. Typically large, complex cells composed of a cell body and many processes. Most neurons have three functional components: receptive or input region, conducting component, secretory or output component. Neuron Cell Body Biosynthetic center of a neuron; contains the usual organelles with the exception of centrioles. Protein and membrane-making machinery (free ribosomes, rough ER) is probably the most active and best developed of any cell in the body. Rough ER referred to as Nissl bodies. Golgi is elaborate and forms an are or complete circle around the nucleus. Mitochrondria are scattered everywhere. Cell body is the focal point for outgrowth of neuron processes. Plasma membrane of the cell body acts as part of the
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Unformatted text preview: receptive surface that receives information from other neurons. Most neuron cell bodies are located within the CNS. Clusters of cell bodies in the CNS are called nuclei. Far fewer collections of cell bodies in the PNS are called ganglia. Neuron Processes Cytoplasmic extensions called processes extend from the cell body. The PNS consists chiefly of neuron processes. Bundles of neuron processes are called tracts in the CNS and nerves in the PNS. Two types of neuron processes: dendrites and axons. Differ from each other in structure and in functional properties. Dendrites (of motor neurons) Short, diffusely branched extensions. Typically contains hundreds of dendrites clustered close to the cell body. Receptive or input regions. Provide an enormous surface for reception of signals from other neurons. Dendrites conduct electrical signals toward the cell body. The electrical signals are not nerve impulses but are short-distance signals called graded potentials....
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This note was uploaded on 11/22/2011 for the course BSC BSC1085 taught by Professor Sharonsimpson during the Fall '10 term at Broward College.

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