From the mouth to the anus [Digestive system]—–el sistema digestivo पाचन तंत्र الجهاز الهضمي 소화기관
How is food digested? How long does it take food to turn into feces? Do you know that from the mouth to the anus is like a pipe? Let’s learn about digestion and …
How long does it take food to turn into feces?
The human digestive system begins with the mouth,
then goes through the esophagus, stomach, small intestine, large intestine,
and ends with the anus.
So from the mouth to the anus is like a pipe.
If all the digestive organs were stretched out, they would add up to 10m.
There are also other organs such as the liver, gall bladder, and pancreas.
However, they do not take up too much space in the body
because these organs are gathered closely in the body, in a zigzag configuration.
Whether someone is skinny or fat, the space occupied by the organs is pretty similar.
How, then, is food digested?
Digestion begins even before food enters the mouth.
When we look at food, or even think about it, saliva is secreted.
Our mouth becomes full of saliva, and is ready to welcome the food.
When we put the food in our mouth,
we chew it with our teeth by moving our jaws to break the food into small pieces.
Also, as secreted saliva mixes with the food,
digestive enzymes (Amylase) decompose carbohydrates into maltose.
This process is called masticatory movement.
Now small pieces of food leave the mouth, and enter the esophagus.
The esophagus is a narrow and long tunnel that connects the mouth and stomach.
Food is moved to the stomach, the next digestive organ, through peristalsis
which is the repeated contraction of the esophagus.
It takes only a few seconds before food reaches the stomach through the esophagus.
Peristalsis of the esophagus delivers food safely to the stomach in any situation.
The esophagus sends food to the stomach
whether we are standing upside down or in zero gravity where things float around!
The Stomach is about 20cm long,
and it is like a pocket that can hold about 1~1.5 liters.
Food that arrives at the stomach stays there for about 4 hours
before going through digestion.
When food arrives at the stomach, the stomach secretes gastric juices
and turns food into a porridge-like consistency.
Gastric juice is hydrochloric acid, a strongly acidic product of about pH2.0
This kills most of the germs in food.
This is why food can stay inside our body for a long time without going bad.
Also, the pepsinogen in gastric juice decomposes protein by being activated as pepsin
when combined with hydrochloric acid.
Pepsin is a weird thing because it can digest food in strongly acidic environments such as gastric juices.
So it has found a good home!
Food converted into porridge in the stomach now moves to the small intestine
through peristalsis of the stomach.
The small intestine is the longest digestive organ, about 6m in length.
It takes 8 hours for food to pass through the small intestine.
Also, when food is moving, carbohydrates, proteins, and fats
are all digested and absorbed by the body.
The first place food arrives after leaving the stomach is the duodenum.
Bile and pancreatic juices are secreted from the duodenum,
and carbohydrates, proteins, and fats are all digested.
Bile helps digest fat.
Amylase, trypsin, and lipase included in bile
decompose carbohydrates, proteins, and fats respectively.
Now the food passes from the duodenum and heads for the small intestine.
Nutrition decomposed into glucose, fatty acids, glycerol, and amino acids
are finally absorbed into the body.
To absorb nutrition more effectively, there are countless villi in the small intestine.
If villi were all spread out, they would cover the size of a tennis court.
This allows a lot of nutrition to be absorbed
when passing through the small intestine.
Now the food, with most of its nutrition gone, moves to the large intestine
Only moisture and anything that has not been digested remains.
The large intestine is a digestive organ approximately 1.5m in length.
Food stays there the longest time, about 10 hours.
It sometimes remains even longer.
There is no digestive enzyme in the large intestine,
so no digestion happens there.
Any moisture remaining in the food is absorbed in the large intestine,
and the remainder is decomposed by germs such as E.coli.
Gas occurs during decomposition, and the remainders become solid.
The large intestine discharges digestive waste products and gas through the anus,
in the form of farts and feces.
Our digestive organs are like a perfectly automated factory.
When material enters,
organs automatically move, decompose, process, and release food.
In this process, much nutrition is decomposed in various digestive organs.
It is absorbed, and turned into the energy necessary for survival.
This digestion repeats continuously over the course of about 24 hours.