According to foreign media reports, an average person consumes 1.5 kilograms of food per day, which is about 550 kilograms of food per year. It’s scary to think about it, 550 kg, which is heavier than two bears!
All of this food we eat feeds hungry cells in our bodies. However, your cells cannot eat an entire salad. So, your body needs to convert the food you eat into smaller molecules that your cells can use. This is the main function of our digestive system. The digestive system, together with the circulatory system, provides “door-to-door meal delivery” services for the cells in the human body.
Without food to digest, we would have no energy to work and play. Not only that, food digestion also allows the body to use the nutrients in the food for self-growth and renewal.
What is the digestive system?
The digestive system is like a biological factory with many organs, glands, and tissues that are responsible for delivering nutrients to us. The digestive system can decompose the food we eat into basic nutrients that can be absorbed by the human body-carbohydrates, proteins, fats, and nucleic acids.
The digestive system consists of seven major organs—the mouth, esophagus, stomach, small intestine, large intestine, rectum, and. From the mouth to the heart, all these organs are connected together by a winding tube of soft tissue and muscle. This tube, we call it the digestive tract or gastrointestinal tract, which is what we often call the intestine.
In addition to these seven major organs, there are three glands that provide additional help. These are: the liver, pancreas, and gallbladder, each containing glands that secrete chemicals and aid in digestion.
Mouth – turns food into easy-to-swallow boluses
The process of digestion actually starts before you put food in your mouth. The minute you see, smell, or even think about eating lunch, your brain is already sending signals to your gut that it’s ready to digest food. Your mouth is constantly secreting saliva, salivating; your stomach is also preparing digestive juices early.
However, the digestive action doesn’t really begin until you take your first bite of food. The teeth work hard to tear at the food, smashing it into smaller pieces. This process, called mechanical digestion, physically breaks food down into smaller clumps.
At the same time, the salivary glands in our mouth secrete saliva. Saliva is an aqueous liquid that contains various enzymes. Enzymes are proteins that speed up specific reactions. Saliva contains amylase that breaks down carbohydrates, and sublingual lipolytic enzymes that break down fat.
Chewing and saliva work together to turn the food in our mouths into a mushy ball, the bolus. After we swallow a food bolus, it travels down the esophagus to the stomach – which has a lot of acidic digestive juices.
Stomach – Stomach stage of digestion
Going down from the esophagus, the food bolus came to the stomach.
We have previously introduced that the digestive tract is a continuous tubular muscle. When it reaches the stomach, the tubular muscle becomes a pouch muscle. The stomach has many functions. It takes food from the esophagus, uses (stomach acid and enzyme) gastric juice to decompose the food, and then transports the decomposed food to the small intestine. In fact, the stomach can produce about four liters of gastric juice per day.
After the bolus reaches the stomach, this powerful organ secretes large amounts of hydrochloric acid—released by the parietal cells that line the lining of the stomach. This stomach acid is so powerful that it can even dissolve metals. In addition, the stomach produces a thick layer of mucus, which prevents stomach acid from harming the stomach itself.