a) Make sure that the students can distinguish between mechanical and chemical digestion.
b) What role does HCL play with regard to protein digestion and bacteria?
c) What are the roles of the small and large intestines?
he first step of digestion, the cephalic phase, takes place before ingesting food. In this phase, the body prepares itself to digest any food consumed in the near future. Shortly afterwards (hopefully!) biting and chewing take place in order to reduce the food into more easily digested pieces, which is a mechanical process, as well as moistening of the food with saliva, a chemical process.
When swallowed, the food arrives at the stomach for further digestion. The stomach contains several compounds, one of which is hydrochloric acid (HCl), which is, "extremely important for digestion because it starts to denature proteins" (Tucker, 94). This process is pivotal because proteins cannot be digested as they are ingested. They must be broken down before they can be absorbed into the body. In addition, it serves as a neutralizer for foreign bacteria that attempt to infect the body.
As the stomach digests, it slowly releases the dissolving food into the small intestine, the longest piece of the tract. In the small intestine, the food is broken down into small molecules which the body can absorb right through the walls of the intestine and into the bloodstream and lymph system. The liver then releases those nutrients into the bloodstream to travel throughout the rest of the body, and filter poisonous cells out.
Next, the large intestine absorbs the rest of the water and stores the waste until it can be disposed of.
Sheila Tucker, B.E. Pruitt, Jane J. Stein, Benjamin Cummings, Joan Salge Blake, Janice Thompson, Melinda Manore. Nutrition, Health, and Wellness: An Applied Approach VitalSource eBook For DeVry University. Pearson Learning Solutions. 2010.
You May Also Find These Documents Helpful
-
The beginning of the digestive process starts with the smell and sight of food which activate the salivary glands. The mouth is the point at which food enters the digestive tract and continues the digestive process by chewing food. The food is then broken down into pieces and moistened by salivary glands which turn food into a bolus. The bolus goes down the pharynx into the esophagus which connects the pharynx to the stomach. The stomach is an organ that mixes food and secretes gastric juice. The bolus, once in the stomach, is mixed into a semiliquid mass called chime. The stomach is close together with the liver and pancreas but does not get assistance from these organs. The chime then enters…
- 251 Words
- 2 Pages
Good Essays -
When we vomit, the acidic nature of our stomach contents becomes immediately apparent both from the taste and from the burning sensation in our throats. The purpose of this acidity is to kill any bacteria we swallow with our food. In the stomach, digestive enzymes and a muscular churning action combine to reduce our food to a thick liquid called chyme. Chyme exits the stomach through a second sphincter and enters the small intestine. Typically, it takes the stomach about 4 hours to process a meal. The small intestine is about 20 feet long. In the duodenum, the first foot of the small intestine, digestion continues with the breakdown of proteins, fats, carbohydrates, and nucleic acids. Some of the digestive enzymes at work in the duodenum are made by the small intestine itself. Others are made by the pancreas. Pancreatic enzymes play an important role in neutralizing food, which arrives from the stomach in a highly acidic condition. In addition, the small intestine receives bile, a substance that is produced in the liver and stored in the gall bladder. Bile is an emulsifier?it breaks fats into tiny droplets that are more easily attacked by enzymes. Beyond the duodenum, the rest of the small intestine functions primarily in absorbing nutrients into the body. In order to be able to do this efficiently?that is, rapidly?the small intestine has a huge surface area. It is covered with numerous fingerlike projections called villi, each of which is in turn covered with tiny little projections called microvilli. Flattened, the small intestine would fill the area of a tennis court! Digested nutrients are absorbed across the surface of the small intestine into capillaries found inside each villus.…
- 4740 Words
- 19 Pages
Better Essays -
When a human sees or smells food the salivary glands are the first thing to react in the digestive system. Once the food is placed into the mouth, it is then taken over by the teeth, tongue, and saliva. These three are what help make the food moist and small enough to be swallowed. At this point the food then becomes what is called bolus. The bolus is then traveled through the pharynx then esophagus, and into the stomach. When the food travels through the pharynx, the epiglottis makes sure that the food paces by the without interring the lungs. Once the bolus enters the stomach, it is then broken down even further by the acids within the stomach. The bolus becomes a little more digested before leaving the stomach. Once the food is at this stage, it is then called Chyme. Chyme is a semiliquid food. It normally leaves the stomach within two to six hours. The small intestine is what does most of the digesting and takes the nutrients from the food. It has help from the liver, pancreas, and gallbladder. The small intestine is made up of three parts, these parts are called, the jejunum, the ileum, and the duodenum. Anything that is not taken for nutrients in the small intestine goes to the large intestine. At this time it travels through what is called the sphincter. The sphincter prevents any of the food to go back into the small…
- 483 Words
- 2 Pages
Good Essays -
The first digestion process starts at the mouth in which cooked starch is reduced into simpler sugars by the action of ptyalin. Digestion of the remaining cooked starch is completed by amylase in the small intestine where duodenum and pancreas take part. Absorption of simpler sugars as the products of digested starch, take place in the small intestine as well. The digestion of proteins starts in the stomach in which protein molecules are reduced into amino acids by the action of hydrochloric acid and the protein digestive enzymes called proteases. Digestion of the remaining proteins is completed at the small intestines by the action of trypsin, and the amino acids are absorbed into the blood stream. Digestion of lipids starts at the small intestines in which fats and oils are emulsified and digested by the enzyme called lipase into fatty acids. Vitamins and minerals are generated and absorbed in the large intestines. The discussion will focus on the digestion of ingested…
- 1938 Words
- 8 Pages
Better Essays -
It receives partially digested food (known as chyme) from the stomach and plays a vital role in the chemical digestion of chyme in preparation for absorption in the small intestine.…
- 664 Words
- 3 Pages
Good Essays -
|intestine for chemical digestion. This is where the food is further broke down into even smaller molecules by protein enzymes in |…
- 500 Words
- 2 Pages
Good Essays -
Digestion first begins with the mouth. When you put food into your mouth your teeth and saliva helps to break down food into small molecules that absorbs into your bloodstream, your tongue finishes this process off by pushing the food into your throat in order for you to swallow. Food then goes through the esophagus and the esophagus muscles pushes the food into the stomach. While in the stomach digestive juices such as enzymes and acids assists in breaking down the food into paste. The food and digestive juices mixes and remains in the stomach for at least two hours. After departing the stomach food then goes through the small intestine. This is the most important part of digestion. The food paste travels through the small intestine and nutrients such as carbohydrates, minerals, proteins, fats, and vitamins are absorbed by villi and then goes through the bloodstream. The food which is undigested then goes through the large intestine as paste. Water is taken from the paste and it then becomes solid waste. The solid waste gathers inside the rectum which is at the end of the large intestine. Lastly, the waste goes through the anus (Hillendale Health, 2013).…
- 689 Words
- 3 Pages
Good Essays -
The digestive system takes in food from your environment and then breaks it down to smaller molecules. Through the process of digestion, your body breaks large nutrient molecules into even smaller molecules; these smaller molecules enter the intestine and are then absorbed…
- 1012 Words
- 5 Pages
Good Essays -
d. The villi are the surface area of the cells exposed to food passing along the gut. It has hundreds of tiny hairs Parts of the Digestive System of a Wolf 1. The liver is where food enters further down the small intestine It helps neutralize and also breaks down fatty molecules in the stomach The yellowish liquid is called bile. The bile is in the liver and stored in the gallbladder 2. Small Intestines is where things break down proteins and fats.…
- 1764 Words
- 8 Pages
Good Essays -
Cited: Cherif, J. V. (2011 ). Nutrition, Health, & Wellness: An Applied Approach . Pearson Custom Publishing .…
- 473 Words
- 2 Pages
Good Essays -
Gastric juice in the stomach begins protein digestion with peristalsis continuing to mix the food, which eventually forms a fluid called chyme that travels to the small intestine. The chyme is absorbed into the intestine with some of the nutrients being absorbed into the bloodstream with water and minerals being reabsorbed into the blood in the colon, while the waste is…
- 552 Words
- 3 Pages
Good Essays -
When the burger reaches the stomach, the epithelium, or stomach wall, secretes gastric juice which has a very high concentration of hydrochloric acid and breaks up the burger. In the gastric juice is also an enzyme that hydrolyzes proteins called pepsin. This pepsin starts out as the inactive pepsinogen, and is activated by hydrochloric acid in the epithelium. After this, the burger is churned in the stomach and becomes chyme, or vomit.…
- 362 Words
- 1 Page
Good Essays -
Then, the body absorbs the smaller molecules through the walls of the small intestine into the bloodstream The bloodstream then delivers the small molecules to the rest of the body. After this, the food continues into the large intestine, and out your body. What happens during the chemical digestion in the mouth, stomach, and small intestine? The process of digestion begins in the mouth when the food is chewed, being broken down into simpler nutrients, and is mixed with saliva.…
- 678 Words
- 3 Pages
Good Essays -
Once I have taken a bite out of my delicious favorite meal, the digestive system gets to work. It all begins in the mouth, chewing the food small enough to swallow. Salvia is squirted into the food to moisten and soften the food. Salvia contains enzymes, which break down the starches in food. Once the tongue forms the food into a ball to be swallowed, it is sent down the pharynx. The pharynx contains sphincters that help keep your food down once you swallow. Next, it makes its way to the esophagus, which is simply a transportation tube from the mouth to the stomach. It then reaches the stomach, which uses chemicals to make the food particles tinier. These chemicals are called gastric juices and include hydrochloric acid and enzymes. Once the stomach mixes with the chemicals, it is formed into a cream-like liquid called chyme. The gallbladder takes over from here hitting the food with more chemicals, one of them called bile. Bile is mixed with our food breaking down the fat into droplets, which will supply us with energy later on. From there, the pancreas uses digestive juice to break down…
- 471 Words
- 2 Pages
Satisfactory Essays -
Part of the digestive system, the large intestine, serves also as an organ of elimination, ridding the body of the waste material, or feces, resulting from the digestive process.…
- 5068 Words
- 21 Pages
Powerful Essays