Digestive system
Digestion reduces food into molecules, these tiny substances called nutrients.
The cells are fed with it to transform them into matter and energy, and they reject the waste resulting from the transformation!
The journey of a pizza
Digestion starts before your first toothache!
When you see or feel the food,
Your mouth is filled with saliva produced by salivary glands located on either side of the jaw!
Saliva contains chemicals that begin to decompose the food.
A tunnel of nine meters!
When you eat a bite of a food,
The teeth begin to reduce it to pièces smaller and smaller.
At the same time,
The food mixes with the saliva thanks to the movements of the tongue.
When the food becomes soft and easy to swallow, the tongue pushes it into the bottom of the throat.
The food then begins its journey into the esophagus.
This tube at the back of the trachea is lined with muscles that contract
To push food like toothpaste coming out of a tube!
When she reaches the stomach, the serious things begin.
Consisting of three distinct muscularlayers, the stomach crushes, kneads while mixing them with the digestive juices for three hours!
I'm tired just to think of it!
At this point, our pizza is just a thick soup!
One pizza at a time!
This thick soup then passes from the stomach to the small intestine through a "door"
Called a sphincter.
Here it is the Duodenal sphincter.
The small intestine has a role of most importance, new digestive juices are produced by its walls, that of the liver and the pancreas and will be excreted to reduce the food in nutrients!
In addition, the small intestine consists of several layers, including a muscular layer.
It is lined with microvillosity, thus considerably increasing its absorption surface!
The liver stores these juices in a small bag attached to its postero-inferior facade called
The gall bladder!
Thus, these digestive liquids are always available!
The nutrients are now so small that they cross the wall of the small intestine to the blood.
Then the blood stream transports them all over the body!
Note also the presence in very large numbers of neurons in the small intestine!
Remarkably, when one observes the physical similarity between brain and intestines(compacted both in circonvolutions) structures yet supposed so different!
Here's the exit!
What remains of the food then passes into the large intestine.
There, the body reabsorbs the water and leaves the solid part to continue.
This solid waste arrives in the rectum,
A sort of reservoir.
Finally, this waste is evacuated in the form of stools by the anus.
Our mouthful of pizza will have made ninemeters of way from the esophagus!
