DIGESTIVE SYSTEM

   The major function of the digestive system is to break down and digest the nutrients which we take in and to transfer it into the rest of the body at the cellular manner. There are many chemical and physical reaction in the system in order to break down the large particles of food which are ingested into smaller, more usable molecules level which can be used by the cells at a cellular level. The digestive system consists of the mouth, esophagus which is the gullet, stomach, small intestine and lastly the large intestine which can be called the colon. This is the organs in the digestive system which i will later elaborate more on it later.

1. MOUTH:

The digestion of food begins in the mouth. Food is partly broken down by the process of chewing and by the chemical action of salivary enzymes which is produced by the salivary gland which also break down starches into smaller molecules.

2. Esophagus/Gullet:

After the food that is being chewed and swallowed, the food enters the esophagus. The esophagus is a long tube that runs from the mouth to the stomach. It uses rhythmic, wave-like muscle movements to force food from the throat into the stomach. This muscle movements gives us the ability to eat and drink.

3. Stomach:

The walls of the stomach consists of various layers of powerful muscles. Those muscles serve as an important mechanical function which causes the stomach to churn, breaking down food into simpler substances. In addition, gastric juice created by the glands that line the stomach are mixed with the food particles. The gastric juices contain pepsin, a digestive enzyme that begins to break down proteins in the mixture and hydrochloric acid that creates proper environment for pepsin to work.

4. Small intestine:

It is made up of three segments which is the duodenum, jejunum and ileum which is 22-foot long with muscular tube that breaks down food using enzymes released by the pancreas and the bile from the liver. The duodenum is responsible for continuous breaking down of food with the jejunum and ileum for absorption of nutrients into the bloodstream. Contents of small intestine start out semi-solid that is mixed with digestive secretion from the pancreas and the liver and end in a liquid form after passing through the organ. After the nutrients has been absorb, the leftover-food residue liquid is then passed down to the large intestine.

5. Large intestine/Colon

The large intestine is largely responsible for absorption of water from the faeces. Intestinal contents are liquid when they reach the large intestine but are normally solid when they reach the rectum.