Nervous system can be defined as a composite network of cell or nervesthat facilitates the relay of messages to and from the brain and the spinal cord to the rest parts of the body it also coordinates the body’s actions. Nervous system is made up of two major hemispheres: central nervous system and the peripheral nervous system. While the central nervous system (CNS) consists of the spinal cord and the brain, the somatic nervous system and the autonomic nervous system makes up the peripheral nervous system. The paper discusses the functions of different part of the nervous system their differences and how the process by which the messages are relayed to and from the nervous system.
As outlined above, the nervous system has two major parts that are the Central and the peripheral nervous system. The two hemispheres carry out a different function within the nervous system, therefore, meaning they are different right from their structure and the functionality. Based on the structure the two differ in that, the CNS is mainly composed of the spinal cord and the brain while the PNS consists of the sensory and the motor neurons in the somatic and the autonomic nervous system respectively. The other difference based on their structure is the size of the cells where the nerve axons of the central nervous systems are extensively shorter compared to those of the PNS (Chiras, 2013). The main function of the CNS is to process any sensory information and determine the proper response. The primary function of PNS, on the other hand, is to relay the information gathered by the sensory receptors in the brain or the CNS for interpretation. This brings out the difference between the two based on their functions.
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Autonomic nervous system (ANS) is one of the major components of the PNS. Its function is involuntary as it regulates the functions of the internal organs of the body, for instance, the heart, respiratory rate, digestion rate among others. This is enhanced by its two divisions that are, the sympathetic and the parasympathetic divisions which at times work Contrary to ensure that the body processes are regulated.
The brain is the most sophisticated part of the human body. It has a complex anatomy which consists of various parts that perform different functions thus making up a brain. One of the most critical parts of the brain is the cerebellum which is situated behind the top part of the brain. Its function is to receive information from the sensory systems and coordinates the voluntary movement (Chiras, 2013). The medulla oblongata is also another part of the brain that coordinates and regulates the involuntary processes of the body such as breathing, digestion, circulation and respiration. The brain responds to the information it receives from the neurons. Different types of neurons relay different information to the brain. For instance, the sensory neuron sends the information of the outside stimuli which can be through touching, smelling hearing or tasting to the CNS thus stimulating the brain to act on the information.
The information to the brain is communicated through a process called the synaptic transmission which involves the neurotransmitters as their primary medium for communication. The process is broken down into four main steps. The first step is the synthesis of the neurotransmitters which are then stored in the vesicles to allow the cell to pass along any action potential that arrives at the nerve endings. The second step is the release of the neurotransmitters from the terminal into the synaptic cleft when any action potential arrives (Brenner et al. 2013). The released neurotransmitters are then recognized by at the postsynaptic neuron by selective receptors to allow them to pass along the information and induct a new action potential. The sensory receptors block the information from the other neurons which are connected to the postsynaptic neuron. Once the information has been passed the neurotransmitters are then inactivated to avoid continual occupation of the postsynaptic cells receptor sites. The inactivation of the neurotransmitters frees up the receptor sites so that more neurotransmitter molecules can be received in the case of another action potential. However, production of high levels of the neurotransmitters leads to psychiatric disorders because it allows numerous impulses and information to be passed into the brain which leads to delusions and hallucinations. It can also lead to addiction as addiction is highly related to motivation and the pleasure of abusing substances. Therefore the production of the neurotransmitters sensitive neurons which are normally concentrated in the substantia nigrans which is the part of the brain that controls motivation and pleasure are triggered by the use of the stimulants such as alcohol.
References
Brenner, G. M., & Stevens, C. W. (2013). Pharmacology. Philadelphia, PA: Elsevier/Saunders.
Chiras, D. D. (2013). Human Biology . Burlington: Jones & Bartlett Learning, LLC.
