Cardiac muscle fibers are a type of striated muscle found only in the heart. The cells are usually connected to each other by intercalated disks. Note the dark band of the intercalated disk that separates two muscle cells. Nerve cells are called neurons . Each neuron has a cell body, an axon , and many dendrites .
Neurons transmit nerve messages.
Glial cells are in direct contact with neurons and often surround them. The neuron is the functional unit of the nervous system. While variable in size and shape, all neurons have three parts. Dendrites receive information from another cell and transmit the message to the cell body. The cell body contains the nucleus, mitochondria and other organelles typical of eukaryotic cells.