Structure of the neural tissue : The nervous system consists of nerve cells and glial cells. NERVE CELLS • The basic unit of the nervous system is the NERVE CELL or NEURON (Fig 8-2) . • In humans, the brain contains 5x10 11 neurons. • Although neurons can be classified into many different types, as you will learn in more detail in Kin 306, they share common features. Neurons share 3 common characteristics with all living cells: 1. They produce energy via the oxidation of nutrients, 2. They are self-sustaining, 3. They are able to repair themselves. In addition, neurons possess at least 2 other specific functions: 1. the transmission of electrical impulses, 2. the capacity to synthesize and liberate a special class of chemical messengers, the neurotransmitters. Neurons are classified as being one of the following: (Fig. 8-3) 1. afferent or sensory neurons: neurons that convey sensory information from the periphery to the central nervous system. 2.
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