22.10.2021

Digestion and absorption of food 

What is digestion?

The function of digestion

• Mechanical digestion

• Chemical digestion

• Biological digestion

Digestive process

Digestion mechanism

What is digestion?

The "sugars," "lipids," and "proteins" that make up food are large molecules (grains) that have a complex structure.

Therefore, it is impossible to take it into the body as it is.

In order to be easier for nutrients to be absorbed, it is necessary to break them down into small pieces.

The function of finely decomposing at this time is called "digestion".

Most of the digested nutrients are absorbed in the small intestine.

The function of digestion

The function of digestion is divided into the following three.

Mechanical digestion

Food is chewed in the human mouth and mixed, agitated and transported in the digestive tract.

What is the digestive tract?

A tube through which food is digested connects in the order of "mouth → esophagus → stomach → small intestine (duodenum, jejunum, ileum) → large intestine → anus".

Chemical digestion

It is the action of digestive enzymes contained in digestive juices to break down food into substances that are easily absorbed by the body.

What is a digestive enzyme?

It is an enzyme secreted from the digestive organs such as the stomach, pancreas, and small intestine, and is used to break down what you eat to a size that can be taken into the blood.

Biological digestion

It is fermented and decomposed by intestinal bacteria.

What is fermentation decomposition?

It is a phenomenon in which organic substances are decomposed to produce specific substances by the action of microorganisms.

Digestive process

Food is ingested through the human mouth and is gradually digested and absorbed.

After being digested and absorbed, it takes about 24 to 72 hours (1 to 3 days) to be excreted as unnecessary stool.

Digestion mechanism

By knowing the mechanism of digestion, you can know the internal structure of the body, so let's study.

After passing through the oesophagus, food stays in the bag-shaped stomach for a while.

At this time, it mixes well with the strongly acidic gastric juice in the stomach.

In the stomach, food is melted into muddy and then moves to the duodenum.

In this duodenum, it mixes with digestive juices.

One of them is bile, which is temporarily stored in the gallbladder after being made by the liver.

As the stomach becomes more active, the stimulus is transmitted to the gallbladder, causing bile to flow into the duodenum at once.

Since bile is alkaline, it has the effect of neutralizing stomach acid in the duodenum.

Digestive enzymes are secreted from the pancreas on the back of the stomach, and digestive enzymes have the role of breaking down what you eat into nutrients such as glucose and amino acids.

In addition, gastric juice, bile, and pancreatic juice secreted from the digestive tract are said to be 6 litters a day, and if you include the water and saliva of what you eat, the total amount is 9 litters.

Ultimately, this 9 litter of nutrient is absorbed into the body as it travels through the long, thin small intestine as as a liquid.

English is my second language, so you may find incorrect sentences.

It would be great help if you leave a comment for me. 

Thank you for reading!