The is composed of two main cell types the neurons and glial cells. Neurons transmit nerve messages and glial cells are in direct contact with neurons and often surround them. The basic function of the nervous system is as follow. They receive sensory input from internal and external environment, the integrate the input a they respond to stimuli. The nervous system also consists of senses.
These senses are: pain, vision, taste, smell, and hearing. The neuron is the functional unit of the nervous system, which have three parts: the dendrites, cell body and axon. The dendrites receive information from another cell and transmit the message to the cell body. Now the cell body is the one that contains the nucleus and the rest of the organelles in the eukaryotic cell. The axon conducts messages away from the cell body. Three types of neurons occur.
The first one is the Sensory neurons that typically have a long dendrite and a short axon, and carry messages from the sensory receptors to the central nervous system. The second one, the Motor neurons has a long axon and short dendrites and transmit messages from the central nervous system to the muscles. The last one is the interneurons, which is found in the space of the connection between one neuron and the other one. The nerve message has its own mechanism also. For example the plasma membrane of neurons has an unequal distribution of ions just like other type of cells.
The outside of the membrane has a positive charge, and inside there is a negative charge. Passage of ions across the cell membrane passes the electrical charge along the cell. This process is called the sodium-potassium pump. How does it work? Well, the sodium ions are more concentrated inside the membrane, while potassium ions are more concentrated inside the membrane by the active transport. Now then the sodium ions are pumped out of the cell and potassium ions are pumped into the cell, restoring the original distribution of ions.
Some axons are wrapped in a myelin sheath formed of specialized glial cells that serve as supportive nutrition to the neurons. This myelin sheath I s also known as Schwann cell. These cells have a gap between which is called the node of Ranvier and they serve as point along the neuron for generating a signal. This also allows the brain to communicate with the rest of the body.
Another important information on the nerve system I s what a synapses mean. Synapses are a junction between a nerve cell and another cell. Neurotransmitters are stored in the synaptic vesicles containing chemicals. The nervous system that is in charge in controlling almost every organ in our body is divided into two parts: the Central Nervous System (CNS) and the Peripheral Nervous System (PNS).
The CNS includes the brain the spinal cord. The PNS consist of the body nerve is the body. The CNS is composed of the brain that this ones is composed also with three parts: the cerebrum, the cerebellum and the medulla oblong ata. The other part the spinal cord runs along with the dorsal side and the links the brain to the rest of the body. As you can see, the nervous system is very important because deals with all the movement in our body. The nervous system parts that all together make their function.
The nervous system in general we can say that I s a very complex system.