The mouth and the salivary glands are the beginning of the digestive tract and digestion begins before the first bite of food is taken. The salivary glands can be triggered by the smell of food, which then secrete saliva, causing the mouth to water. The saliva increases once food has actually been tasted and the structure of the salivary glands begins to relate to its function. The mouth begins to chew and break down food into small pieces that can eventually be digested. More saliva is produced in order to begin the procedure of breaking down food so that the body can absorb it.
The first function of the digestive system is the intake of food; the mouth is responsible for this as this is where food enters the body. Enzymes inside the mouth serve two purposes, one is to kill bacteria and two, begin digestion. Salivary Amylase begins to breakdown starch, carbohydrate in our food. Lingual lipase is an enzyme that stays neutral in the mouth but is active when it reaches the stomach. You should note that enzymes are like tiny biochemical machines that disassemble large macromolecules like proteins, lipids carbohydrates into smaller molecules, the breakdown of these foods continue throughout the digestive system until they are ready to enter the blood stream by absorption.
This includes swallowing and peristalsis which is involuntary. This is where the food moves along the muscle contractions of the alimentary tract. It consists of alternation and contraction of smooth muscle in the wall of the GI tract to squeeze food downwards. 3) Mechanical digestion consists of a physical process of breaking food into smaller pieces through mastication (chewing of food) before being broken
It begins in the mouth, where food is taken into the body and chewed to break it into smaller pieces, then amylase – a digestive enzyme produced in the body – is added to it through human saliva. Amylase is a carbohydralase and breaks down the carbohydrates within a food. This allows the body to take some of the nutrients from the food straight away. Once the food is swallowed it enters the pharynx before it is transported to the oesophagus, the pharynx converts the food into bolus. Bolus is chewed food which had been broken down with various enzymes produced in the mouth, it is much easier to digest than food which has just been chewed.
Once the food has been swallowed is goes down the oesophagus where the involuntary muscle movements help push the food to the stomach. Once the food reaches the stomach the process called digestion begins; the acids in the stomach make a very hostile environment for bacteria to survive one of the main acids in the stomach is called hydrochloric acid. Once all the bacteria in the stomach is killed the food passes through to the small intestine and the process called absorption begins. The large food molecules are broken down in the small intestine and the nutrient are absorbed by the micro villi. Once all the nutrients in the food has been absorbed the process called elimination begins this is when the broken down food is no longer needed and is eliminated out of the rectum.
Most of the needed material is later returned to the blood. Urine flows from the kidneys through the ureters, and down into the urinary bladder, where it is stored. The kidneys act as filters and contain about 1 million tiny nephrons. As urine forms, they maintain homeostasis by regulating the water level in our
The small intestine leads to the large intestine, another tube for which absorption takes place. In the large intestine fluid is reabsorbed back into the bloodstream and faeces is formed; the faeces exits through the anus. Although these are the main organs involved in digestion, they are supported by the accessory organs. These include; the liver, gallbladder, pancreas, and salivary glands. Figure 1 (below) shows the location of these organs (madders.s, 2007).
The small intestine digests most nutrients and the nutrients are absorbed into the body. From there the food and fibers finally then enters the colon where it is absorbed and forms stools. The last part of the colon, the sigmoid colon and rectum stores the stools before being excreted. The colon consists of six sections including the ascending colon, the transverse colon, the descending colon, the sigmoid colon, the rectum, and the anus. The intestinal walls consist is three layers.
Bulimia and Anorexia Nervosa Compare and Contrast Essay Rough Draft There are many disorders that can be detained within the human body. One of the most common disorders are eating disorders in which people feel the need to starve themselves, binge, or binge and purge. This simply means the person will stop eating completely or they will eat large amounts of food and force themselves to get rid of all the food in their bodies by vomiting, using laxatives, diet pills, and etc. Two of the most common eating disorders are Bulimia and Anorexia Nervosa. Though these two disorders have many similarities, they are also different in many ways.
Advocates and Mediators in Eating Disorders Amanda Miller 5/18/2014 BSHS/441 Joseph Compton Eating disorders is a form of mental illness. There are different eating disorders and as a mediator or advocate it is important to know the difference between the two. People who are looking into working with those who suffer from eating disorders should know the following: Anorexia Nervosa is self-starving or extreme weight loss. Bulimia is having episodes were a person’s consumes food and then self-induces vomiting. Binge eating shares the same characteristics as bulimia except for the person eats rather large amounts of food and then induces vomiting.