Did You Know?
The entire process of digestion can take anywhere from 24 to 72 hours to complete!
Digestion is the process by which the larger molecules of food are broken down by enzymatic action into simple components that can be absorbed and assimilated by the body. In humans, digestion takes place in the digestive tract that begins with the mouth and ends with the anus. The digestive system consists of the organs that function in the breakdown of the complex molecules present in the food, into smaller chemical compounds that can be readily absorbed into the bloodstream.
General Facts About the Digestive System
In addition to the organs of the digestive system, there are many other organs that assist in the process of digestion. The process of digestion is not simple and involves many steps. Let's learn more about the digestive system through a series of facts that illustrate the amazing functioning of the human body.
► The digestive system consists of the following organs.
- Mouth or oral cavity
- Gall bladder
- Small intestine
- Large intestine
► The organs of the digestive system are hollow, and the inner walls are lined with mucous membrane (mucosa). The mucous membrane that lines the mouth, stomach and small intestine, consists of glands that secrete digestive enzymes to aid in digestion.
► The organs also contain a smooth muscle layer that assists in breaking down the food particles. This layer contracts and propels the food particles downwards along the digestive tract by a process called peristalsis.
► In addition to the hollow organs of the digestive tract, the digestive system consists of two solid organs, viz., the liver and the pancreas. These organs are responsible for secreting digestive juices (e.g., bile) that reach the intestine via small tubes, referred to as ducts.
► The esophagus is the passage between the pharynx and the stomach. In an adult human, it is 10 to 14 inches in length and about 1 inch in diameter.
► It is the gallbladder that stores the digestive juices secreted by the liver, until they are required by the small and large intestines. If the gallbladder is removed in case of a medical illness, an individual can continue to live a normal life, provided he/she takes certain precautions regarding his/her diet.
► In the process of digestion, food entering the mouth is masticated by the teeth and partly broken down by the saliva. Then, the partly digested food passes through the esophagus and travels down to the stomach, where it is acted upon by acidic secretions.
► The stomach is a muscular sac-like organ which serves as the principal organ of the digestive system. The walls of the stomach are lined with three layers of muscles.
► The digestive juices produced by the stomach are acidic in nature. When the food chewed in the mouth reaches the stomach, the exposure to the acidic environment of the stomach, reduces the chewed food to pulp.
► The stomach performs three major functions - storing the swallowed food, mixing the food with the digestive juices, and emptying the digested food into the small intestine.
► The function of the pancreas is to secrete the hormone insulin, along with enzymes that aid in the process of digestion.
► The digestive juices secreted by the pancreas contain enzymes for catalyzing proteins, fats and carbohydrates; whereas the liver produces bile juice for digesting fats.
► The walls of the small intestine absorb the useful nutrients, which are transported to other parts of the body via the bloodstream.
► Inner walls of the small intestine are covered with microscopic finger-like structures known as villi, which protrude into the intestinal cavity and increase the effective surface area of the small intestines by more than 500 times.
► In contrast to the highly acidic environment of the stomach, the environment of the small intestines is alkaline.
► The appendix is a tube-like structure that extends outwards from the wall of the small intestine, and is located at the junction of the small intestine and the large intestine. It is a vestigial organ, which means that it does not perform any function. Vestigial organs are believed to have lost their original function(s) through the process of evolution.
► From the small intestines, the food residues move to the large intestines and are passed out as feces.
► The rectum extracts moisture from the food residues, and the feces is expelled through the anus.
► The large intestine consists of three parts: cecum, colon, and rectum.
Some Amazing Facts...
► The stomach of an adult human being can hold up to 1.5 liters of water!
► You can have more than 400 types of bacteria in your large intestine!
► The liver is the second largest organ in our body, the skin being the largest organ.
► Our liver performs more than 500 different functions!
► The volume of hydrochloric acid produced by the stomach per day can reach up to 2 liters!
► The salivary glands secrete about 1-3 pints of saliva a day.
► During the process of digestion, food stays in the stomach for 2-3 hours.
► One of the lesser known functions performed by the mouth is to increase or decrease the temperature of the food that we intake, in order to make it equal to the body temperature.
► We are born with more than 10,000 taste buds! These are located on the tongue, the throat, and on the roof of the mouth.
► The cells that make up the lining of the stomach get replaced continuously, and a completely new lining is formed every 5-10 days!
► The highly coiled small intestines measure 20 feet in length. They also absorb 90% of the food nutrients.
► Every year, the average human being consumes over 500kg of food!
► By the time we are 70 years old, the quantity of enzymes produced in our body becomes half the amount produced when we are in our twenties!
► The liver is the only organ in the human body that has the ability to regenerate itself completely!
► It takes around 6 hours for the average human to digest a meal that is high in fat content. A meal rich in carbohydrates, on the other hand, takes around 2 hours to digest.
► About 11 liters of fluid, digestive juices and digested food, is circulated in the digestive system, of which only 100 milliliter is excreted as waste.
Well, these were just a few important facts about the human digestive system. It is to be noted that the circulatory system and the nervous system, also play a major role in the functioning of the digestive system. Digestion is the catabolic process of breaking down the complex food materials into simpler forms or nutrients that can be easily absorbed into the bloodstream. The circulatory system carries the nutrients to the various cells of the body, to nourish and provide them with the source of energy. For a person to stay healthy and fit, proper functioning of the digestive system is necessary.