Wednesday, 23 November 2011

Digestion and Good Health

The role of gastrointestinal tract is to give the body water, nutrients, and electrolytes. That is  for doing this the system must be able to do five main processes:
  • Moves food through the system
  • digest the food with enzyme secretions
  • absorb what has been digested
  • distribute the nutrients to the blood for transport
  • eliminate the waste products
The food will be going through the digestive tract following various changes. First of all the food is taken into the mouth and chewed, which makes the particles into smaller. At this time the salivary glands secrete an enzyme called ptyalin that starts to digest sugar. After swallowing the food passes through the esophagus and to the stomach where hydrochloric acid is secreted to begin digesting protein. For further digestion of protein pepsin is secreted. The food is mixed with the enzymes and passed into the small intestine where pancreatic enzymes begin to break the food into smaller and smaller pieces. These pieces are broken down into units small enough to pass through the walls of the small intestine into the blood. The blood then distributes the nutrients to rest of the body. The remaining undigested waste material is passed into the colon and eliminated.

Digestion is in short is about taking big things and making them smaller so that they can fit into our blood stream and finally into our cells. Enzymes are chemicals in our digestive tract that break proteins, carbohydrates into smaller and smaller units necessary for absorption.

Proteins consist of amino acids linked together. Digestion of protein involves breaking down the big, long chains of amino acids into smaller and smaller chains, so that they can get into the system.

Carbohydrates consist of glucose molecules linked together. Starch is a long-chain carbohydrate made up of many glucose molecules linked together. The larger molecules are broken down into smaller ones and eventually into a single molecule of glucose that we can absorb into the blood stream.

Fats consist of fatty acids and glycerol(triglycerides). Fat is digested when the fatty acids and the glycerol are separated, so that absorption into the blood can occur.

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