Peristalsis also is at work in this organ, moving food through and mixing it with digestive secretions from the pancreas and liver. The duodenum is largely responsible for the continuous breaking-down process, with the jejunum and ileum mainly responsible for absorption of nutrients into the bloodstream. Pancreas-The pancreas secretes digestive enzymes into the duodenum, the first segment of the small intestine. These enzymes break down protein, fats, and carbohydrates. The pancreas also makes insulin, secreting it directly into the bloodstream.
Mechanical digestion in the mouth helps begin chemical digestion by mixing the food with enzyme-containing saliva. After leaving the mouth, a swallowing reflex moves food from the pharynx into the esophagus. Peristalsis then moves food through the esophagus, which is separated from the stomach by a ring of muscles that controls the passage of food called a sphincter. The stomach, an organ consisting of smooth muscle, is divided into cardiac, fundic, body, pyloric regions and a pyloric canal. The functions of the stomach include mixing and churning food with gastric fluid to produce chyme, storage of ingested foods, controlling passage into the small intestine (through the pyloric canal), and protein digestion.
The saliva will help to break down the molecules in your food because it has a special chemical. Following the saliva come the main organs that are in the system. Once you take a bite, the food will be grinded into smaller and smaller pieces. When your teeth and salvia have made the food soft and easy to swallow, your tongue pushes it back of your esophagus to be swallowed. Then the esophagus pushes the food to the stomach, and that’s when things really start to happen!
The hydrochloric acid helps convert pepsinogen to pepsin which is needed for protein digestion. Gastrin is a hormone that stimulates production of hydrochloric acid. The small intestine is where most of the nutrients are absorbed. The large intestine is where the waste is produced, water absorption occurs, and electrolytes produce vitamins. In order for the human body to function to its fullest ability, we must take in the required amount of nutrients.
Instead, the acids work to break down the food for easier digestion in the intestines. As the food is broken down to a thick paste-like substance known as chyme, it moves past the pyloric sphincter and into the small intestine. The first section of the small intestine, the duodenum, secretes digestive enzymes like amylase, maltase, sucrase, lactase, lipase and pepsin, to break down the chyme into even smaller parts that the body can then convert into usable energy. Some other organs that secrete chemicals to aid in the digestion process include the pancreas, liver, and gall bladder. The pancreas secretes trypsin and chymotripsin.
Bolus is simply food in its chewed state. The bolus is then swallowed and enters the stomach. In the stomach, food or bolus is further digested with the stomach acids and is broken down even further to prepare to enter the intestinal tract. The stomach contracts and relaxes to push digested food into the small intestine. Once inside the small intestine, enzymes are released that allow the usable parts of the food to be absorbed into the body for energy.
Digestion of carbohydrates begins in the mouth as mentioned earlier with the enzyme amylase which is present in the saliva. This breaks the carbohydrates into their simpler subunits (saccharide forms). In the stomach, the carbohydrates are converted into chyme with the peristaltic action of the stomach. Next, the chyme will pass into the duodenum. At the introduction to the duodenum, alpha amylase is secreted by the pancreas and further breaks down the carbohydrates into primary simple sugars.
The small intestine is the principal site of digestion and absorption. Enzymes from the pancreas, liver, gallbladder, and the small intestine itself combine to break down nutrients so that they can be absorbed. The pancreas supplies enzymes to digest proteins, fats and carbohydrates. The live produces bile required for emulsification of fat, and the gallbladder stores the bile until it is needed. The absorption of nutrients in the small intestine is facilitated by tiny projections called villi, which provide more surface area for absorption.
Examples of foods with carbohydrates include bread, potatoes, rice and pasta etc. | Lipids (fats) | Lipids are known for making cell membranes, these cell membranes then protect and insulate organs from heat loss and is also used as a source of energy. Lipids contain vitamins A, D and E (fat soluble vitamins) which help in the production of the hormones oestrogen and testosterone.Fat supplies us with energy and makes it possible for other nutrients to function well too. Examples of foods that contain lipids are butter, cheese, tuna and olives etc. | Proteins | Proteins are big molecules that have important roles in the body.
It is our secondary source of energy however carbohydrates are quicker to digest. Animal sources of protein include meat, fish, poultry, eggs and dairy products. They provide us with all the essential amino acids and are known as complete proteins. Incomplete proteins are proteins from plant sources like breads, cereals, legumes, nuts and some vegetables. We need fat to provide our bodies with energy, to help protect our bones and organs as well as insulating our body.