The Autonomic Nervous System Essay Example | Topics and Well Written Essays - 1750 words

The Autonomic Nervous System - Essay Example Each pathway comprises of a preganglionic neurone as well as a postganglionic neurone. Within the sympathetic system, the synapses between these two neurons are located near the spinal cord. On the other hand within the parasympathetic nervous system, these two neurons are located near to, or within the effector organs (Tortora & Derrickson 2009). The effects of the sympathetic and parasympathetic nervous systems normally oppose each other. They are termed as antagonists, thus is one system contracts a muscle, the other usually relaxes it. The balance between the two systems concisely regulates the involuntary activities of the organs and glands. Exceptional to note is that it is feasible to control consciously specific activities of the autonomic nervous system through training. Some examples in this include control of the anal and bladder sphincters. With regard to nerve impulse transmission process, the sympathetic nervous system stimulates effectors and produces noradrenalin as t he neurotransmitter at nerve junctions. In contrast, the parasympathetic nervous system inhibits effectors and produces acetylcholine at the nerve junction, otherwise called the synapse (Tortora & Derrickson 2009). The autonomic nervous system comprises of motor neurons which innervate smooth and cardiac muscles as well as the glands. These neurons also ensure optimal environments conditions within the systems to ensure maximum support for body activities. The neurons operate via subconscious control and have viscera as most of their effectors. Within the autonomic nervous system, the preganglionic fibers release acetylcholine as the major neurotransmitter. Postganglionic fibers release norepinephrine or acetylcholine whose effects can either be stimulatory or inhibitory. The neurotransmitter effects within the autonomic nervous system on target organs are dependent on the neurotransmitter released. Additionally, such effects are dependent on the type of receptors expressed on the e ffector organs. The divisions of the autonomic nervous system serve similar visceral organs but cause opposite effects. These divisions exemplified by parasympathetic and sympathetic categories help in maintaining homeostasis. Precisely, the sympathetic division mobilizes the body during activity while the parasympathetic division conserves the energy within the body. The role of parasympathetic division is well illustrated when a person relaxes after taking a meal. In such a circumstance, the division plays a role of keeping the energy level consumption as low as possible. As such, the heart rate, blood pressure and respiratory rates are kept at lower concentrations. However, during such circumstances, the gastrointestinal tract activity is high as a result of digestion. The skin is warm while the pupils are constricted. On the other hand, the sympathetic division is a good depiction of fight or flight system. This division allows the regulation of activities during exercises. In s uch scenarios, the system reduces the flow of blood to organs while it increases the flow of blood to muscles. Its activity is illustrated by an individual who is under a threat and as such, the heart rate increases with rapid and deep breathing. Additionally, the glucose levels in the blood are high because this important sugar is released from the liver. Furthermore, the skin is cold and sweaty while the pupils of the eyes are dilated due to alertness. Parasympathetic div