The function of nervous tissue is to transmit and receive external and internal stimuli. Consisting of two basic types of cells, neurons and glial cells, nervous tissue represents a fundamental aspect of living organisms and can be considered the seat of response to stimuli. Signals from the internal or external environment are received by the neurons and then transmitted as electrical impulses to muscles, glands, the central nervous system or other neurons.
The glial cells in nervous tissue are the protective cells. They make up about 90 percent of nervous tissue and surround many of the processes that occur there. Their function is to provide support, nutrition and insulation for the neurons. The glia that are found within the central nervous system, which consists of the brain and spinal cord, are called neuroglia.
There are three types of neurons: motor neurons, sensory neurons and interneurons. The motor neurons move the action potential from the central nervous system to the effector organs, such as muscles or glands. The sensory neurons function in the opposite manner, moving the action potential from the sensory organs to the central nervous system. The interneurons act as connectors between neurons.
Overall, neurons are responsible for the reception, propagation and conduction of nerve impulses. The sensory and motor neurons are found mostly outside of the brain and spinal cord, while the interneurons are found entirely within the central nervous system.