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Digestive system

The digestive system is a set of organs that are responsible for the process of digestion; It is known as such to the modification of food, so that the cells of the body can absorb its nutrients.

The functions that the digestive system performs broadly are four. In the first place, it is responsible for transporting food from the mouth to the stomach. Second, it secretes gastric juices so that they can be absorbed. Third, it assimilates nutrients from food. And finally, through defecation, it expels the waste.

What is the digestive system and how does it work?

The digestion of the food we eat is a long process, in which a large selection of organs are involved and a wide range of functions and processes take place.

It all starts with chewing food in your mouth ; the enzymes are responsible for degrading these foods since otherwise it would be impossible to swallow those of large size. Once the food has been chewed, it begins its descent through the pharynx into the esophagus; the latter is in charge of transporting food to the stomach.

The stomach is a kind of warehouse in which the gastric juices are found ; thus, once the food reaches the stomach, said juices are responsible for breaking it down.

The food then continues its way through the intestines ; in this organ takes place the absorption of those nutrients from food that are necessary for the proper functioning of the body, as well as from water. This is what is known as the nutrition process . Those foods that do not provide any type of beneficial nutrient are eliminated through urine and feces.

Although it is a long process, in which a great variety of organs intervene and different functions take place, it takes between two and five hours . However, it is important to know that there are certain foods that can take longer, even several days, to be absorbed by the body. There are two factors that influence the duration of the digestive process: amount of food consumed and basal metabolism.

Structure and organs

The structure of the digestive system is one of the most complex in the human body; It is approximately 10 to 12 meters long , which means that it is six or seven times the length of the body. The different organs that compose it cover the entire trunk; the digestive system begins in the face and ends in the pelvis.

Parts of the digestive system

Below we explain in detail the different parts of the digestive system.


It is in the mouth that the teeth are responsible for grinding the food we eat, so that is where the digestion process begins . The tongue has a fundamental role, and it is that it greatly facilitates the passage of food into the esophagus. And, of course, saliva , which is responsible for destroying the bacteria that carry food; without it it would be extremely difficult to digest food.


It is shaped like a tube and its function is essential; is responsible for allowing air to pass into the lungs, and food into the esophagus. The pharynx is connected to the nose, mouth, windpipe, and esophagus.


It is made up of a muscular pathway approximately 30 centimeters long . Its main function is to transport food to the stomach, being very important in the digestion process. The esophagus is also part of the respiratory system since it is the way through which we expel gases.


The stomach acts as a warehouse, since its main function is to store the food that arrives through the esophagus. Thus, the gastric juices of the stomach break down the food we eat, so that it can continue on its way to the small intestine.

Small intestine

The small intestine is the organ that activates signals related to appetite . Its main component is the duodenum, which ingests food, while absorbing nutrients from it.

Large intestine

One of the most important organs of the digestive system, which fulfills a large selection of functions. On the one hand, the generation of feces. On the other hand, the absorption of water, as well as potassium and sodium. In addition, the colon generates antibodies, which are essential to protect the digestive system from any type of abnormality or disease. And finally, the large intestine is responsible for absorbing water, thus preventing us from becoming dehydrated.


The main function of the pancreas is the production of hormones that make it easier to digest food . In addition, this organ is responsible for maintaining blood sugar levels at their correct values. Read our article on the function of the pancreas .


The liver is considered the most important organ in the body thanks to its wide range of functions. It is responsible for producing bile , which is very important for both digesting and absorbing fat. In addition, it is the liver that eliminates those toxic substances that are stored in the body. All this without forgetting that it is this organ that filters the blood.

Anus and rectum

They are the final parts of the digestive system. They collect the remains of food, store it and control its expulsion. Thanks to the anus and the rectum we can control bowel movements . Therefore, they fulfill a transcendental role.

Hormones of the digestive system

Several hormones are involved in the digestive process, which are interesting to know.

  • Gastrin: gastrin is the most important hormone of all since it stimulates the movements of the digestive system, thus avoiding what is known as gastric reflux. In addition, it is the one that is responsible for releasing the acid responsible for the dissolution of food.
  • Secretin: stimulates the production of the enzyme that absorbs proteins. In addition, it participates in the generation of bile by the liver.
  • Cholecystokinin: intervenes in the secretion of pancreatic juice.
  • Ghrelin: this is a hormone that regulates appetite, so it has a very important role. It sends a series of signals to the brain, in a way that allows us to control the amount of food we eat.
  • Peptide YY: this is the hormone responsible for stopping cravings once the digestive system is satisfied.

Functions of the digestive system

In the following points we explain what are the main functions of the human digestive system.

  • Chewing food: food is chewed in the mouth with the help of saliva and teeth; Thus, what is known as a food bolus is formed, which is swallowed.
  • Swallowing: once food has been swallowed, swallowing allows it to reach the esophagus.
  • Transport to the stomach: the stomach plays two very important roles in the digestive process. For one thing, it retains the bolus. And, on the other hand, it allows the chemical degradation of food, as well as the absorption of certain nutrients such as vitamin B12.
  • Absorption of nutrients and water: the small intestine is responsible for absorbing the nutrients present in food; meanwhile, the colon is responsible for absorbing water.
  • Evacuation: and, finally, the evacuation of waste through feces, which pass through the rectum into the anus.
You may also be interested in:   How to eliminate intestinal gas?

Most frequent diseases

Below we indicate which are the main diseases of the digestive system, the ones that occur most frequently.


  • Cancer of the esophagus: Cancer of the esophagus begins in the inner lining of this organ. Thus, as the disease progresses, cancer cells invade the rest of the layers.
  • Stomach cancer : it is the most common type of malignant tumor of the digestive system. About 95% of stomach cancers that are diagnosed are what are called adenocarcinomas; They originate in the glandular cells, responsible for producing gastric juice.
  • Pancreatic cancer: practically all pancreatic cancers start in exocrine cells, which are responsible for regulating fat metabolism.
  • Cancer of the small intestine: This is a rare malignant tumor that originates in the glandular cells of the lining of the organ, which are very close to the stomach.
  • Anal Cancer : About 80% of malignant tumors in the anus are squamous cell. If it is a primary cancer, there is the possibility of removal as long as there is no metastasis.

Hiatal hernia

The hiatal hernia occurs when the upper part of the stomach happens to be located in the chest rather than the abdomen . It is a relatively common condition, affecting around 20% of the population.

The most common symptoms of this disease are heartburn, continuous discomfort in the abdomen, problems swallowing food, and bad breath. When the proper treatment is not established, eating becomes a practically impossible mission, so that those who suffer from hiatal hernia often suffer a remarkable loss of weight.

Regarding the causes of hiatal hernia, if it occurs in children it implies that it is congenital; that is to say, the smallest have already been born with it. In the case of adults, the most common causes of this condition are obesity or smoking; It occurs especially in people over 50 years of age.


The constipation is a disease of the digestive tract that is characterized by people who suffer have bowel movements every two or three days . The most common cause of this condition is a diet low in fiber; It can also occur due to the administration of certain medications, as well as stress and anxiety.

The symptoms are different in each patient. However, the most common warning signs are the following: bowel movements less than three times a week, difficulty in having a bowel movement, hard stools that cause pain when defecating, and gas.

Ulcerative colitis

Ulcerative colitis is a disease that causes inflammation of the lining of the rectum and colon . Although it can occur in people of any age, it generally occurs in young people, between 15 and 30 years old.

It is a relatively easy condition to diagnose since the symptoms are very clear: severe fatigue, weight loss, rectal bleeding, skin sores, abdominal pain and diarrhea.

For the diagnosis of colitis, doctors perform a blood test, as well as a stool exam. Sometimes an imaging test such as a colonoscopy is necessary to detect the disease.


The hemorrhoids , also called piles, is a disease characterized by inflammation of the veins of the anus and the lower rectum. Its causes are very varied, being a great effort when evacuating one of the main ones. This condition is also common in pregnant women due to increased pressure in the veins during the gestation period.

It is a very common disease; It is estimated that 75% of the population suffers from hemorrhoids at some time in their life. Sometimes they do not present any symptoms, although sometimes they lead to a great feeling of discomfort, as well as itching and bleeding.

Irritable bowel syndrome

Irritable bowel syndrome, also known by its acronym IBS, is a disease of the digestive system that causes abdominal pain , as well as certain variations in the intestine. It generally begins in adolescence, being much more frequent among women.

One of the main causes of this condition is stress. It must be taken into account that the intestine and the brain are connected by both hormonal and nervous signals; thus, stress can cause the intestines to become more sensitive.

Tips to take care of the digestive system

Taking care of the digestive system is essential as it plays a very important role in the proper functioning of the body. Below we point out a series of tips and advice to take care of it.

  • Food: adequate nutrition is the most important thing to take care of the digestive system. Olive oil is one of the best foods for your health since it significantly reduces stomach acidity and, in addition, it has a great laxative effect. Of course, it is essential to follow a diet rich in fiber to avoid diseases such as constipation. And finally, fruits and vegetables are essential because they have antioxidant properties and, in addition, they provide a large amount of water and nutrients.
  • Fatty foods: it is important to avoid the consumption of fatty foods as much as possible: fatty meats, sausages, cream, cured cheeses … When cooking, better with vegetable oils.
  • Large meals: It is also highly recommended to avoid large meals. The ideal is to eat five meals a day; breakfast, lunch, lunch, snack and dinner.
  • Gases: you have to control the gases. For this it is important to chew food slowly and swallow it carefully.
  • Physical exercise: and, finally, physical activity is also very important to promote the health of the digestive system. Activities such as walking favor the mobility of the different organs, thus helping the digestion and elimination of food.
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Hello Readers, I am Nikki Bella a Psychology student. I have always been concerned about human behavior and the mental processes that lead us to act and think the way we do. My collaboration as an editor in the psychology area of ​​Well Being Pole has allowed me to investigate further and expand my knowledge in the field of mental health; I have also acquired great knowledge about physical health and well-being, two fundamental bases that are directly related and are part of all mental health.

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