Chemical digestion employs enzymes to break down food, whereas mechanical digestion requires muscular activities such as chewing and muscle contractions. Chemical digestion can only break down protein into amino acids while mechanical digestion can break down all three major nutrients: protein, carbohydrate, and lipid.
In chemical digestion, the acidic nature of the stomach breaks down carbohydrates and proteins into their simple sugars and amino acids, respectively, which are then absorbed through the intestinal wall into the blood for use by the body. Mechanical digestion takes place in the gut where digestive juices containing enzymes produced by pancreas and small intestine digest the food mechanically.
The three main parts of the mechanical digestive system are the mouth, esophagus, and intestines. The mouth begins the process by breaking down food into smaller particles that can be more easily swallowed. It also adds moisture to the food before it enters the esophagus. The esophagus is a long tube that leads from the mouth to the stomach. The function of the esophagus is to transport food from the mouth to the stomach while protecting itself from harmful substances in food. The last part of the mechanical digestive system is the large intestine or colon. The large intestine is where most of the work of digestion occurs.
Mechanical digestion entails physically breaking down food ingredients into smaller bits so that chemical digestion may take place more efficiently. Chemical digestion is responsible for further degrading the molecular structure of ingested chemicals by digestive enzymes into a state that may be absorbed into the circulation. The digestive system also contains glands that produce digestive juices that play a role in the digestion process.
Stomach acids break down or digest the food we eat, making it easier for our bodies to absorb the nutrients from the meal. The stomach is divided into two parts: the fundus and the body. The fundus is the top portion of the stomach where hydrochloric acid and enzymes are most concentrated. Food moves from the fundus to the lower part of the stomach where more acid and enzymes are present. Digestion continues until all the nutrients have been extracted from the food, at which point an intestinal segment called the duodenum receives the chyme (the product of digestion). This material is then passed into the jejunum, followed by the ileum, and finally expelled from the body as stools.
The major glands of the gastrointestinal tract include the pancreas, liver, and intestines. All these organs work together to provide energy for their respective functions through the synthesis of glucose from protein and fat molecules found in the diet. The intestines also contain many microscopic plants called crypts that produce some hormones that regulate metabolism.
Mechanical digestion is the physical act of breaking down food without the use of chemicals. Mechanical digestion begins with the physical process of mastication in the mouth (chewing). Food is broken down by the specialized teeth as it is sliced by the incisors, ripped by the cuspids, and ground by the molars. The saliva helps to soften the food so that it can be chewed more easily and also contains enzymes that begin the chemical digestion process.
Once food enters the stomach, the muscular walls squeeze the contents into smaller bubbles. This increases the exposure of the food to gastric acid, which breaks down protein into amino acids and destroys most bacteria. The pancreas produces an enzyme called protease, which is used by other digestive juices to break down protein into small molecules that are easier for the body to absorb. Protease is also added to some commercial meat and dairy products to help speed up the digestion process.
In the small intestine, the remaining undigested material is called chyme. Water is absorbed from the chyme into the blood cells to create a fluid that is transported to all parts of the body and aids in lubricating joints and providing fuel for muscles. The small intestine is divided into three sections: the duodenum, jejunum, and ileum. The duodenum is where water is absorbed from the chyme and minerals are added back into it before it enters the jejunum.
Digestion is classified into two types: mechanical and chemical. Mechanical digestion is the process of mechanically breaking down food into smaller bits. As the meal is eaten, mechanical digestion begins. Chemical digestion includes breaking down food into simpler components that cells can utilise. The saliva contains enzymes that start this process.
In the oral cavity, both mechanical and chemical digestion take place. Saliva plays an important role in both processes. Without saliva, we would be unable to digest our meals because it contains enzymes that break down food into nutrients our bodies can use. Mechanical digestion occurs when chewing moves the food through the oral cavity and breaks it up into smaller pieces that are easier for the digestive system to deal with.
This process starts in the mouth when muscles in the jaw and tongue move food around as you chew it. The teeth also play a role in this process by breaking down food into smaller pieces. Between bites, saliva flows into the empty spaces between your teeth where it was not able to flow during previous meals. This saliva contains enzymes that start the chemical digestion of your next meal. The stomach and intestines are full of natural acids that help break down food further but these acids cannot reach all parts of the food volume so some ingredients require additional assistance from enzymes found in saliva.
After eating a meal, there is a delay before the body can process all of the food and extract the necessary nutrients required by the body.