The nervous system’s composition is made up of the nerve tissues, nerve tissues are the building blocks of the nervous system of our body. The function of the nerve tissues is to receive stimuli and transmit the stimuli to the nervous center and initiate a response to the stimulation. The nervous system can be separated in two major parts – the central and peripheral nervous system. The most basic part of the nervous system is neuron which is not only the sensor but the communicator for the external and internal stimuli.
The central nervous system controls the brain and the spinal cord thus serving as the collective point for the nervous impulses. Let’s take a closer look at them.
Central Nervous System
The part of the nervous system that comprises of the brain, spinal cord and the brainstem in the vertebrate makes the central nervous system. Since the central nervous system comprises of the three major parts of the body, it controls majority of the bodily functions and the brain being the center of what we do or think controls this system. Just like a central computer this system interprets the information that it gets from our nose (smell), tongue (taste), eyes (sight), skin (touch), ears (sound) including the internal organs like the stomach. The spinal cord is the proverbial highway that communicates between the brain and the body. This is why when the spinal cord gets injured and this communication gets interrupted parts of the body stop functioning or get paralyzed.
Peripheral Nervous System
The nervous system comprises a large number of nerves that link to the spinal cord and the brain. This system is also divided into two parts-somatic and autonomic nervous systems. The peripheral nervous system consists of the spinal nerves, their roots and branches, peripheral nerves, neuromuscular junctions and the cranial nerves. In fact anterior horn cells, though technically is part of the central nervous system is at times discussed with peripheral nerves as they are part of a motor unit. Here bundles of nerve fiber or axons conduct information to and from to the central nervous system.
The two parts have their own functioning. The autonomic nervous system is the part that concerns with the involuntary response and movement of structures like the heart, glands and the smooth muscles inside the body. This nervous system is distributed throughout both Peripheral and the Central Nervous System. On the other hand it is the somatic nervous system that is responsible for regulating the movements of the skeletal muscles.
The neurons are connected by synapses. Each neuron has its own cell body that has extensions called axons and a dendrite that conduct the nerves impulses. The dendrites are the receptors of signal. The signal received by the dendrite gets transmitted towards the cell body of a neuron in form of electronic impulse. This impulse gets transmitted away from the cell body to other neurons and glands via axon, muscles that terminates at the synaptic bouton. The motor neuron carries the signals away from the Central Nervous system.
The nervous system takes advantage of chemical and electrical means to help all the parts of the body communicate properly with each other. The brain and spinal cord form the central nervous system, the bundles of nerves are the peripheral nervous system and the building blocks are neurons, all together making up the nervous system of our bodies.