The gastrointestinal system
The digestive system, also known as the gastrointestinal system, comprises the digestive tract or the alimentary canal through which ingested food passes from the mouth to the stomach and a number of different organs. Every one of these organs, including the alimentary canal, performs particular functions during the process of digesting the ingested food.
- The digestive tract or alimentary canal
- The digestive tract or the alimentary canal stretches from the mouth to the anus. The major function of the digestive tract is to digest as well as assimilate the ingested food into our body. The digestion and absorption of the ingested food as well as expulsion of the waste products as excreta is a multifaceted as well as complicated procedure, wherein each section of the digestive tract performs an exclusive function.
All through, the digestive tract has a coating of a slender film of cells known as intestinal mucous membrane. Typically, the cells comprising the intestinal mucous membrane increase or proliferate at a rapid pace and hence, these cells are highly susceptible to treatments administered to combat cancer. When the food is placed in the mouth, it is chewed and mixed with saliva secreted by the salivary glands present in the mouth. Subsequently, the softened food is swallowed and it goes to the stomach traveling through the esophagus or the gullet. In fact, use of radiation and chemotherapy to fight cancer are likely to have an influence on the salivary glands as well as the taste buds - diminutive glands present on the tongue and utilized to savor food. In such cases, the patients will experience problems in savoring foods and may have dehydrated mouths. Although not often, people taking chemotherapy or radiation may also experience symptoms called mucositis - formation of reddish blemishes and a smoldering feeling in the mouth), or esophagitis - inflammation of the gullet due to burning while swallowing food.
In addition to digesting and absorbing food, the stomach also serves as a pool where ingested food may be stored for a number of hours. The stomach secretes certain acids that are mixed with the food and breaks it up with a view to facilitate the absorption of the nutrients present in the food into the body. However, it must be noted that the stomach is responsive to medicines, such as aspirin and cortisone and may also act in response to stress by escalating the intensity of acids secreted by it. Nevertheless, such reactions may deteriorate into a medical condition called gastritis (inflammation of the stomach resulting in heartburn). However, it is possible to alleviate these symptoms by drinking water or milk. In addition, at times, the reactions of the stomach acids may also cause ulcers - profound corrosion of the stomach wall. It is important to note here that in case of gastritis and stomach ulcers which are not treated timely, they may result in stomach hemorrhages. Use of specific medicines to treat trauma, strain and inflammation may result in disorders in the movement of the stomach that may frequently lead to conditions, such as vomiting and nausea.
The digestive system also includes the duodenum, a small intestine and the large intestine that form a long tube measuring around 21 feet or seven meters in length. While the small intestine absorbs the solid foods, the large intestine assimilates the ingested liquids. When an individual is administered treatment to combat cancers, the mucous membranes or the coating of cells inside these organs usually stop their assimilation actions. Consequently, the patient may suffer from upset stomach and diarrhea. Often, physicians try to overcome such inaction of the mucous membranes in the duodenum, small intestine and the large intestine to absorb food by feeding the patients by administering intra-venous injections.
The good thing is that the entire negative after effects in the digestive tract or alimentary canal caused by treatments, such as radiation and chemotherapy, administered to cancer patients are actually revocable and the organs return to their normal functioning soon after the treatment is stopped.
- The pancreas
- The pancreas is a part of the digestive system and performs two diverse activities. Pancreas helps in the digestive process by producing pancreatic juices that are secreted into the duodenum. These pancreatic juices enclose enzymes that are crucial for digesting sugars, meats and different types of fats. Another utility of the pancreas includes secretion of hormones, among which insulin is the most important. Insulin is important for the body as it sustains the accurate intensity of glucose in the bloodstream. In fact, any decline in the amount of insulin secreted by the pancreas results in diabetes. It is important to note that certain substance like usage of alcoholic beverages and some drugs may cause harm to the pancreas. In addition, sometimes formation of stones obstructing the opening of the pancreas may result in a condition called pancreatitis (congestion and tenderness of the pancreas). Although pancreatitis may cause severe discomfort to the patient, this condition seldom occurs when an individual is being treated with anti-cancer therapies.
- The liver
- The liver is a comparatively big, glandular organ with a reddish-brown hue to be found in the upper right side of the abdominal cavity. The liver is divided into five lobes or parts through crevices and is a very vital organ that performs the maximum number of functions. The liver plays a crucial role in the digestive process by secreting bile, which is necessary for assimilation of fats. In fact, bile is stored in the gallbladder before it is secreted into the duodenum. In addition, the liver also produces several proteins - the most prominent among them are albumin and the proteins involved in the vital process of blood coagulation or formation of blood clots. The liver also helps in getting the body rid of natural wastes produced by different organs as well as residues of different drugs. Moreover, the function of the liver in the anti-cancer treatment courses is of tremendous importance.
It may be noted here that the liver is susceptible to a number of drugs, venomous substances and also to specific viruses. In addition, the bile duct is often blocked by the formation of gallbladder stones resulting to the jamming of the liver. Although rare, development of cancerous growth known as the lymphoma or cancer of the pancreas also causes liver congestion. Occasionally, inflammation of the liver occurs either owing to lymphoma or gallstones and such a medical condition is called hepatitis.
The liver of a patient receiving chemotherapy is scrutinized regularly as well as closely, as hepatitis caused by use of certain drugs is quite common. The liver is examined by means of regular blood tests and whenever there is any sign of harm to the liver owing to the use of any medication, the drug is stopped immediately. Alternately, physicians may even change the dosage of the medication or administer an altogether different treatment.
Occasionally, some specific spreading blood ailments like different types of leukemia and lymphoma may affect the liver. In addition, the liver may be affected owing to bone marrow transplants caused by reactions between graft and host. In such cases, the physician usually recommends a biopsy to ascertain or cancel any diagnosis.