The digestive system is a set of organs that are constituted to be able to process food and that have as an objective to decompose and transform into food for the cells of the body.
The digestive system consists of different parts. Each of these performs a fundamental task for the transformation of the food.
The process of digestion is similar in all mammalian animals. In this device, food is ingested through the mouth, processed with the help of different enzymes and glands that converts them into nutrients for the body. That food that does not serve as a nutrient is discarded by urine or as fecal matter.
The digestive process commonly takes between 2 and 4 hours. However, certain nutrients can be completely assimilated by the organism after several days of ingestion.
Characteristics Of Digestive System
1. Function of the digestive system
The digestive system aims to convert food into proteins so that the body’s cells are fed. However, the process can be defined in 4 stages or steps:
transportation (receives food),
secretion (breaks down food through gastric juices),
absorption (transforms into nutrients),
excretion (those foods that do not serve as nutrition are eliminated from the body).
The food enters through the mouth. It is thanks to the teeth that food can be crushed. In addition, the tongue helps in the mixing of food with saliva and forms a paste (called bolus) that is then transferred to the esophagus.
3. Chewing and saliva
During the chewing of food, (which occurs in the mouth) saliva plays an essential role since it breaks down some of the food to form the food bolus that will pass to the stomach. On the other hand, saliva also promotes digestion and helps destroy bacteria that enter through the mouth.
4. The pharynx
Then, the food passes briefly through the pharynx. This is a tube through which both the oxygen and food air circulates and is located in the neck. Then the food goes through the esophagus that in humans has a path of 30 cm long.
This muscle is the one that carries food to the stomach. It is located in the neck and is part of the digestive system but also through there passes oxygen, therefore it is part of the respiratory system and the digestive system at the same time.
There is a kind of cap (the epiglottis) located in the larynx (respiratory system) whose function is to close the trachea so that the food is diverted to the pharynx and does not continue through the esophagus. When this fails and a drop of saliva or a food particle continues down the esophagus, a violent coughing and drowning occurs that makes the food return to the mouth immediately.
Already in the stomach food is mixed with gastric juices. These juices allow the disintegration of the food bolus. In turn this allows them to pass already to the small intestine.
7. Small intestine
This is divided into 3 parts: the duodenum, the jejunum and the ileum.
The duodenum It measures 25 cm in length and is responsible for absorbing nutrients, especially iron. It is the duodenum responsible for activating the signs of hunger.
The jejunum It measures between 1.5 and 2.5 cm long and is between the duodenum and the ileum. The function is to absorb the substance of the food. In this part carbohydrates, proteins and lipids are broken down to a minimum.
The ileum It measures 7.5 cm long. It is responsible for the absorption of vitamin B12 and the absorption of already digested foods.
8. The large intestine and the anus
The large intestine can be subdivided for study in 4 parts: the cecum, the colon, the rectum and the anal canal.
The blind. It has the shape of a sack and has many substances that facilitate the digestion process.
The colon It is the largest part of the large intestine and is subdivided into:
The main function of the colon is to convert the liquid of the small intestine (called chyme) into feces. Vitamins K and B are also produced here. Also in this part of the digestive system antibodies are created.
The rectum. This section measures between 15 and 20 cm. Its function is to collect the waste eliminated in the process previously and retain it until then it expels it.
The anal channel. It measures around 4 cm in length. In the walls of this channel there are internal and external muscles called sphincters that control the excretion of the body’s fecal matter.
9. Associated organs or glands
The function of the attached organs serves to break down food and facilitate digestion and absorption of nutrients in the body. These glands are:
Salivary glands. They are those that are in the mouth and secrete saliva. This saliva serves to moisten foods but also fights some bacteria found in food.
Gastric juices These juices are in the stomach. They also facilitate the decomposition of nutrients into nutrients.
Liver. This is the largest gland in the human body. They have the function of making bile (through which fat is absorbed). It also detoxifies the body and stores vitamins. The gallbladder is located inside the liver. Here the bile produced in the liver is stored and will be used when the food is in the duodenum.
Pancreas. It is responsible for the secretion of insulin. This is essential for the regulation of blood sugar. Failure in the pancreas generates Diabetes disease.
10. The work of enzymes
During digestion, both proteins and carbohydrates and lipids are transformed into simpler units thanks to the intervention of enzymes. In this way, they can be absorbed and transported by the blood.