SYL5

1. The absence of bile or pancreatic juice
The digestive system of an organism is quite a complicated system and it is influenced by many factors and substances as well as by a large number of different chemical elements. Any changes, even the slightest ones may produce a significant influence on the work of the organism at large and digestive system in particular.
At this respect it is noteworthy the role that pancreatic juice play in the process of digestion. The reason is that pancreatic juice is the major source of lipases, or fat-digesting enzymes while bile emulsifies fat, thereby increasing the ability of lipases to digest fatty food. Moreover, bile is also necessary for absorption of the products of fat breakdown. In such a way pancreatic and bile juices are very important because without them little fat breakdown and absorption can occur.
Consequently, the natural result of the absence of pancreatic and bile juice is fatty stool because fat consumed by a human being cannot be normally absorbed in the organism as it happens when there is sufficient amount of pancreatic and bile juice. The knowledge concerning the role of pancreatic and bile juice is very important, especially for a RN because it provides him/her with information about a proper nutrition and needs of human body making possible better functioning of digestive system due to a carefully arranged diet.

2. The enteric nervous system as a part of the parasympathetic and sympathetic nervous system
The enteric nervous system is quite complicated and it is closely linked to the parasympathetic and sympathetic nervous system. Generally speaking the enteric nervous system consists of two principle components, they are two networks or plexuses of neurons, i.e. the myenteric and submucous plexus, both of which are embedded in the wall of the digestive tract making it possible to speak about this system as a ‘gut brain’. The myenteric plexus is located between longitudinal and circular layers of in the tunica muscularis and exerts control primarily over digestive tract motility. The submucous plexus is buried in the submucosa and its role is in sensing the environment within the lumen, regulating gastrointestinal blood flow and controlling epithelial cell function.
In fact the enteric nervous system can and does function autonomously. At this respect it is possible to speak about this system as independent one but at the same time normal digestive function requires communication links between this intrinsic system and the central nervous system. These links take the form of parasympathetic and sympathetic fibres that connect either the central and enteric nervous system or connect the central nervous system directly with the digestive tract. Through these cross connections, the gut can provide sensory information to the CNS and the CNS can affect gastrointestinal function. Connection to the CNS also means that signals from outside of the digestive system can be relayed to the digestive system, for instance the sight of appealing food stimulates secretion in the stomach.
This knowledge is particularly important for a RN because the understanding of the role of the enteric nervous system and its close link to the parasympathetic and sympathetic nervous system provides the possibility to recognize the malfunctioning of the system as the cause of digestive tract diseases, including small intestinal motility disorders, gastric outlet obstructions and megacolon and properly treat these diseases.

Bibliography:
1. Parker, R. The Enteric Nervous System. Chicago: New Publishers, 1998.
2. Robertson, C.W. The Digestive System and Body Metabolism. CA: McGraw Hill, 2001.
3. Thompson, K. Introductory Anatomy. New York: Routledge, 2000.
4. Winston, W. The Digestive System. Cambridge: Cambridge University Press, 1997.