Discover the basics of the digestive system and its key functions, as well as 10 fascinating characteristics of this vital bodily system that is responsible for breaking down food, absorbing nutrients, and eliminating waste.
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 is responsible for breaking down food into smaller molecules that can be absorbed by the body and used for energy, growth, and repair. It includes organs such as the mouth, esophagus, stomach, small intestine, large intestine, and anus, as well as accessory organs like the liver, pancreas, and gallbladder that help with digestion. The digestive system also plays a role in immune function and hormone regulation.
The mouth is the first organ in the digestive system and is responsible for beginning the process of breaking down food. The mouth contains several structures that aid in this process, including the teeth, tongue, and salivary glands.
Teeth are responsible for physically breaking down food by chewing and grinding it into smaller pieces, which makes it easier to swallow and digest. The tongue helps to mix the food with saliva, which contains enzymes that begin breaking down carbohydrates. Salivary glands secrete saliva in response to the presence of food in the mouth, and it also helps to moisten and lubricate the food, making it easier to swallow.
The mouth also plays a role in taste perception. Taste buds on the tongue detect different flavors in food, which can affect our enjoyment of eating and also signal to the brain to begin the digestive process.
3. Chewing and saliva
Chewing and saliva both play important roles in the digestive process.
Chewing helps to physically break down food into smaller pieces, which makes it easier for the rest of the digestive system to process. As we chew, the teeth grind and crush the food, breaking it down into smaller particles. This increases the surface area of the food, which allows enzymes in the digestive tract to more effectively break it down.
Saliva also plays a crucial role in digestion. Saliva is produced by the salivary glands in the mouth and contains enzymes, such as amylase, that begin the breakdown of carbohydrates. Saliva also helps to moisten and lubricate the food, making it easier to swallow.
Additionally, saliva contains bicarbonate ions, which help to neutralize the acid in the mouth and protect the teeth from decay. Saliva also contains antimicrobial agents that can help to prevent bacterial overgrowth in the mouth.
Overall, both chewing and saliva are important components of the digestive process and can affect how efficiently and effectively our bodies break down and absorb nutrients from food.
4. The pharynx
The pharynx, also known as the throat, is a muscular tube-like structure located behind the mouth and nasal cavity. It is an important part of the digestive system as well as the respiratory system, as it serves as a pathway for food and air to pass through.
During the digestive process, the pharynx plays a crucial role in swallowing. When we swallow, food is pushed to the back of the mouth and into the pharynx by the tongue. The muscles of the pharynx then contract, moving the food down into the esophagus and on to the stomach.
The pharynx also contains several structures that help to prevent food and liquid from entering the lungs during swallowing. The epiglottis, a flap of tissue located at the base of the tongue, closes off the entrance to the trachea (windpipe) during swallowing, directing food down the esophagus and preventing it from entering the respiratory system.
Overall, the pharynx is an important part of the digestive system that helps to ensure food is properly directed to the stomach while preventing it from entering the respiratory system.
The esophagus is a muscular tube that connects the pharynx to the stomach in the digestive system. It is about 10-13 inches long and extends from the base of the neck to the diaphragm.
When we swallow, the muscles in the pharynx push food into the esophagus, which then contracts and propels the food towards the stomach through a series of muscular contractions known as peristalsis. The esophagus also contains sphincters at each end that help to regulate the movement of food. The upper esophageal sphincter (UES) controls the movement of food from the pharynx to the esophagus, while the lower esophageal sphincter (LES) regulates the movement of food from the esophagus into the stomach.
The esophagus plays a critical role in the digestive process by ensuring that food is efficiently transported from the mouth to the stomach. It also helps to prevent the backflow of stomach acid into the esophagus, which can cause discomfort and damage to the lining of the esophagus.
The stomach is a muscular sac located in the upper part of the abdomen that is an important organ in the digestive system. It is responsible for breaking down food into a liquid mixture that can be further processed by the small intestine.
The stomach has three important functions in the digestive process. First, it secretes digestive juices, including hydrochloric acid and enzymes, that help to break down food into smaller particles. Second, it mixes and grinds the food with the digestive juices to create a semi-liquid mixture called chyme. Finally, it regulates the release of chyme into the small intestine, which allows for the controlled digestion and absorption of nutrients.
The stomach also has a number of protective mechanisms to prevent damage to the lining of the stomach. The mucous lining of the stomach secretes bicarbonate, which helps to neutralize the acidic digestive juices in the stomach. The stomach also has a thick layer of mucus that acts as a barrier to protect the lining from the corrosive effects of the digestive juices.
Overall, the stomach plays a critical role in the digestive process by breaking down food into a liquid mixture that can be further processed by the small intestine. It also has important protective mechanisms to prevent damage to the lining of the stomach.
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
Enzymes are proteins that play an essential role in the digestive process. They are produced and secreted by various organs in the digestive system, including the salivary glands, pancreas, and small intestine.
Enzymes act as catalysts, meaning they speed up chemical reactions without being consumed themselves. In the digestive process, enzymes help to break down large molecules of carbohydrates, proteins, and fats into smaller molecules that can be absorbed and utilized by the body.
For example, the enzyme amylase, which is produced in the salivary glands and pancreas, helps to break down carbohydrates into simple sugars. Proteases, which are produced in the stomach and pancreas, help to break down proteins into amino acids. Lipases, which are produced in the pancreas and small intestine, help to break down fats into fatty acids and glycerol.
The production and secretion of enzymes is tightly regulated to ensure that they are released at the appropriate time and in the correct location within the digestive system. The digestive process is complex and involves the coordinated action of multiple enzymes to ensure that food is properly broken down and absorbed by the body.