To improve the speed of their communication, and to keep their electrical charges from shorting out with other neurons, axons are often surrounded by a myelin sheath. The axons are also specialized, and some, such as those that send messages from the spinal cord to the muscles in the hands or feet, may be very long - even up to several feet in length. Some neurons have hundreds or even thousands of dendrites, and these dendrites may themselves be branched to allow the cell to receive information from thousands of other cells. This vast interconnected web is responsible for all human thinking, feeling, and behaviour. Figure 4.1 Components of the Neuron.įigure 4.2 The nervous system, including the brain, is made up of billions of interlinked neurons. Figure 4.2 shows a photograph of neurons taken using confocal microscopy. As you can see in Figure 4.1, “Components of the Neuron,” neurons are made up of three major parts: a cell body, or soma, which contains the nucleus of the cell and keeps the cell alive a branching treelike fibre known as the dendrite, which collects information from other cells and sends the information to the soma and a long, segmented fibre known as the axon, which transmits information away from the cell body toward other neurons or to the muscles and glands. A neuron is a cell in the nervous system whose function it is to receive and transmit information. The nervous system is composed of more than 100 billion cells known as neurons. List three of the major neurotransmitters and describe their functions.
Draw a diagram of the pathways of communication within and between neurons.Describe the structure and functions of the neuron.
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