How does the digestive system work?
Allow me to explain what the digestive system is! The digestive system is structured by the alimentary canals of our body which carry out ingestion, digestion, absorption and egestion respectively. The system begins from your mouth when food is ingested to your mouth. Your teeth and salivary glands start the digestion process! Whilst your teeth cuts, grinds and crushes the food into smaller bits, the salivary glands excrete amylase, breaking down carbohydrate polymers to glucose! Thanks to the teeth and amylase, the food becomes a bolus, which is basically chewed food. The bolus then travels through the esophagus, a tube which connects the mouth to the stomach! The bolus is able to move down the tube due to peristalsis, a process of how the muscles of the esophagus pushes the bolus to the stomach! Digestion continues in the stomach, as pepsin (a type of protease) is secreted. The stomach also mixes the bolus with its gastric fluids, producing a substance called Chyme! The chyme then flows to the duodenum, the first part of the small intestines. This is where most of the digestion takes place. Enzymes are secreted by the pancreas and the liver to the duodenum, efficiently breaking down the remaining polymers. The liver produces a substances called bile which helps in breaking down fat. In addition, bile is stored in the Gal bladder. After the duodenum, the substance moves deeper into the small intestines to the ileum and jejunum. Absorption of the digested material takes place in this area by the villi. Once absorption is finished, the substance makes way to the colon, the beginning section of the large intestines. The Colon absorbs water from the substance which has now become faeces, while moving it to the rectum, an area of the large intestines where faeces are temporarily stored before egestion! That is the digestive system! This repeats over and over again!
Learn about the digestive system the fun way!
Had trouble understanding the explanation above? Well I must admit, it is not a simple system and reading about it could be boring and hard to understand! And for that reason, here is an interactive diagram from nationalgeographic.com which could help you learn the digestive system! Try out the digestive system anatomy and explore! |
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HIV affect on digestive system
The gastroesophageal reflux disease Apositivelife.com explains that a person infected by GERD (Gastroesophageal Reflux Disease) happens to have their stomach fluids flow into their esophagus, causing a heart burning sensation. HIV infected people can get the disease, because the treatment medication pills for HIV can cause GERD as a symptom or a side effect.
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Kaposi's sarcomaThe Kaposi's sarcoma is a type of cancer that affects the mouth and skin. webmd.com claims that this cancer which was one rare had become popular due to AIDS and HIV. Due to the weakened immune system, it is said that he body is incapable of fighting off diseases like the Kaposi's Cancer. ncbi.nlm.nih.gov, a peer reviewed source also agrees to the relation of HIV and Kaposi's sarcoma, as it talks about the severity of HIV in those who had Kaposi's sarcoma. In addition to the mouth, this cancer can cause tumor on the stomach, liver and intestines which are all part of the digestive tract. Symptoms of this cancer can vary from having spots your skin to severe vomiting. In the worst case scenario, this cancer can cause death, so be aware!
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