The four major types of animal tissues are (1) epithelial tissue, (2) muscular tissue, (3) connective tissue, and (4) nervous tissue. The nervous tissue is made up of nerve cells (or neurons) and their associate cells such as neuroglia cells. The nerve cells are specialized cells that receive and transmit nerve impulses or action potentials from one nerve cell to the next. The nerve cells have characteristic cellular projections, i.e. dendrites and axons. The dendrites receive the electrochemical signals (from another nerve cell). The axons then convey the action potential to the next nerve cell. The axon has a bulb-like ending called the axon terminal. Neurotransmitters are released from the axon terminal to reach the next nerve cell, eventually transmitting the nerve impulse from one nerve cell to another. Apart from the nerve cells, the nervous tissue also has neuroglia cells. These cells aid in protecting and providing nutrients to the nerve cells. They also help maintain homeostasis and form myelin.
The nervous tissue makes up the nervous system. There are different types of nervous tissue. In the central nervous system, there are grey matter and white matter. In the peripheral nervous system, there are ganglion tissues and nerve tissues.