What does the human digestive system consist of - see images of digestion in each part

The article was professionally consulted with Specialist Doctor I Dong Xuan Ha - Gastroenterologist - Department of Medical Examination and Internal Medicine - Vinmec Ha Long International General Hospital.

Have you ever wondered how the process of digesting food in humans takes place? Is the human digestive system very complicated? The following information will give you a first-hand look at what happens to food during each stage of the human digestive process.

Digestion is a rather complex process, helping to convert food into nutrients that the body can use, for growth, energy, and necessary cell repair. In addition to nutrients, the digestive process in humans produces waste products that are then eliminated from the body.
The human digestive system (also known as the gastrointestinal system) is a long spiral tube, starting from the mouth and ending at the anus. The process of digesting food is made up of a series of muscles, which work together to create a movement that propels the food away and with the help of cells that produce enzymes and hormones to metabolize and break down food. . In addition, there are three other organs necessary for the digestion of food: the liver, gallbladder, and pancreas.

The first station: Mouth Mouth is the "departure point" of the digestive system. In fact, the digestion of food begins before you even start chewing the first bite. Specifically, the smell of food triggers the secretion of saliva, making your oral cavity become wet, ready to "welcome" food. As you begin to taste food, the amount of saliva increases.

By the time you start chewing, the movement of your jaw muscles and teeth helps the food to break down into pieces small enough for digestion. At this time, the salivary glands are active. Saliva contains enzymes that break down food into a form your body can absorb and use. Therefore, eating slowly and chewing food thoroughly will greatly support your digestive system.
2nd station: Pharynx and esophagus The pharynx (or throat) is the part of the digestive tract that receives food down from the mouth. The lower part of the pharynx is divided into two branches, the esophagus and the trachea. The esophagus is the passageway that transports food to the stomach, while the trachea carries air into the lungs.
The act of swallowing takes place in the pharynx, which is a reflex that is both passive and active. The tongue and palate (cleft palate) are two organs that help push food into the throat combined with the reflex to close the trachea. As a result, food through the mouth only has the only way forward is into the esophagus.
The esophagus consists of muscles that combine to form a tube, extending from the pharynx to the stomach. Food is pushed one way through the esophagus into the stomach by a series of contractions, called peristalsis.

Just before entering the stomach, food must pass through the foramen, an important ring-shaped muscle called the lower esophageal sphincter (LES). This sphincter opens only to allow food or water to enter the stomach and closes shortly afterwards to keep them from moving backwards. If for some reason the lower esophageal sphincter is not working correctly, you may have a condition called gastroesophageal reflux disease (GERD), which causes heartburn and a sensation of food being regurgitated. back into the esophagus.

Station 3: Stomach and small intestine The stomach is an important organ for the human digestive system, shaped like a bag, made up of a series of powerful muscles. In addition to storing food, the stomach acts as both a mixer and a blender. The stomach secretes acids and enzymes, which aid in the process of crushing, breaking down and converting food into liquid or paste.

Next, this food mixture will move down to the small intestine and continue the process of food digestion. The interval between meals is when the stomach releases the food residues that cannot be liquefied, which will quickly move down to the intestines and be eliminated.

The small intestine is also an extremely important part of the human digestive system. This is where most of the nutrients the body receives through food are absorbed. Here, food continues to be digested with the participation of intestinal motility, enzymes secreted by the pancreas and bile from the liver. Peristalsis helps push food away and mixes it with digestive secretions from the pancreas, liver, and even bile. Structurally, the small intestine is made up of three segments: the duodenum, the jejunum, and the ileum. The duodenum is mainly responsible for the continued breakdown of food, while the jejunum and ileum are responsible for the absorption of nutrients into the bloodstream.

While food is stored in the small intestine, nutrients are absorbed through the intestinal wall and into the bloodstream. What's left is waste, which continues to move into the large intestine (colon).
All the organs involved in the digestion of food in the upper part of the large intestine, called the upper gastrointestinal tract. All activity from the large intestine onwards is in the lower digestive tract.
4th station: Colon, rectum, and anus The colon (large intestine) is a muscular tube that connects the small intestine to the rectum. Structurally, the colon is made up of the cecum, ascending colon, transverse colon, descending colon, and sigmoid colon, which connects to the rectum. In it, the appendix is ​​a small pouch-shaped organ that attaches to the cecum. The large intestine is a specialized organ, responsible for waste disposal, making the process of defecation (waste excretion) easier and more convenient.

Feces and waste products left over from human digestion pass through the large intestine by peristaltic contractions. First, the stool is in a liquid state. However, as it passes through the colon, liquid stools are reabsorbed and become solid. Stool is stored inside the sigmoid colon (S-shaped) until it receives a peristaltic stimulus strong enough to push it into the rectum (usually this stimulation occurs once or twice daily).

It usually takes about 36 hours for stool to move through the colon. The nature of feces is mainly food debris and bacteria. These bacteria have many very useful functions, such as synthesizing various vitamins, processing waste and food particles, and protecting the body against harmful bacteria. When the amount of waste in the lower colon becomes too much, it will push them into the rectum to start the elimination process.
The rectum is the space that connects the colon to the anus. The functions of the rectum include:
Receiving waste from the colon Giving out signals that trigger our body to carry out the process of excreting stool Store stool until elimination takes place. The anus is the final part of the human digestive system. The anus consists of a series of muscles along the pelvis (pelvic floor muscles) and two other muscles called the anal sphincter (internal and external).
Pelvic floor muscles create an angle between the rectum and anus, preventing waste from passing out unnecessarily. The anal sphincter controls the movement of waste. In particular, the internal anal sphincter is always kept closed (unless stool enters the rectum), in order to control the release of stool and waste while we are asleep or do not feel the need to have a bowel movement. When we feel the urge to defecate, the external anal sphincter prevents the release of stool until we begin to defecate.

In general, the digestion of food in humans is highly dependent on the activity of a large network of nerves, hormones and muscles. If there is a problem with any of these components, the digestive system can malfunction, even dangerous diseases can occur if not treated promptly.
The digestive system includes the digestive tract stretching from the mouth to the anus and many participating organs such as the liver, bile ducts .. so any damage to these organs also affects the digestive system. .
Symptoms are diverse from chest pain, abdominal pain, belching, heartburn, heartburn, stool disorders, jaundice, anemia, weight loss. even life-threatening. Therefore, you should seek medical attention early when detecting any abnormal signs of the digestive system.
Vinmec hospital system provides gastrointestinal endoscopy examination according to Japanese standards with modern equipment to accurately detect digestive problems including early cancer diagnosis and treatment.

Translation source:
https://www.webmd.com/digestive-disorders/digestive-system
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https://www.webmd.com/digestive-disorders/digestive-system
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