Types of Nerve Cell

Nerve cells also are known as neurons transmit and receive electro nerve impulses. They can be found all over the body and are connected all over the body, but can mostly be found near around the Central Nervous System. They are connected to other neurons or to cells in muscles, and or organs. Nerve impulses travel electrically along the neuron and are transmitted by neurotransmitters, which are chemical transmitters, to the next neuron across a tiny gap, called a synapse, between the neuron and the adjacent cell, which is known as the target cell. In addition to neurons, the nervous system contains large numbers of other types of cell, called neuroglia, which protects, nourish, and support neurons.

The three types of neurons are Sensory neurons, Motor neurons, and Interneurons. The first type of neurons is the Sensory neurons, which have to do with touch and being able to feel pain. The sensory neurons can be found in the skin, muscles, joints, and organs that indicate pressure, temperature, and pain. There are some Sensory neurons in the nose and tongue that perceive as tastes and smells. Neurons in the inner ear are sensitive to vibration and provide us with information about sound. The rods and cones of the retina are sensitive to light, and allow us to see. The second type of neuron is the Motor neurons are able to stimulate muscle cells throughout the body. The third neuron is the Interneurons, which are the neurons that provide connections between sensory and motor neurons, as well as between themselves. These neurons are mostly known for their part in the making of the central nervous system and the brain, which are all interneurons.

Neurons come in three functional classes. These classes are derived from the number of cell extensions that are found in the cell body or soma. Unipolar neurons are nerve cells that have one extension connected to the soma. These cells are often used in afferent nervous system function, which means that it involves the senses. Bipolar neurons are nerve cells that have two projections and are used in specialized sense detection, such as in smell and sight. Multipolar neurons are nerve cells that have many cell extensions, including dendrites, which are receiving pathways, and typically one axon, which is a delivering pathway. A typical neuron has all the parts that any cell would have, and a few specialized structures that set it apart. The main portion of the cell is called the soma or cell body. Neurons have a large number of arms extending out. These arms are called dendrites. They often look likes branches from a tree or spines extending out from the cell body. The primary function of the dendrites is to receive chemical messages from other neurons.

Nerve cells have another extension that is different from dendrites. This extension is called axons. The dendrites help neurons connect to each other and to other cells, while the axon helps axon help transmit electrochemical signals through the action potential. Areas with a large number of cell bodies are called grey matter. Longer axons are usually covered with a myelin sheath, a series of fatty cells which have wrapped around an axon many times. They serve a similar function as the insulation around the electrical wire. The end of the nerve fiber has many names such as the bouton, the synaptic knob, the axon foot, and etc. Its job is to convert the chemical signal so that the chemical message can be passed onto the next nerve cell. Between the axon ending and the dendrite of the next nerve cell is a very tiny gap called the synapse (or synaptic gap, or synaptic division/divided).

The surface of the axon contains hundreds of thousands of tiny mechanisms called ion channels. This process is called the action potential. When the charge enters the axon, the ion channels at the base of the axon allow positively charged ions to enter the axon, changing the electrical balance between inside and outside. This causes the next group of ion channels to do the same, this happens all the way down until the end.