Stomach

Your stomach is a part of your body.

It sits between your food pipe and your small gut. The stomach is made of strong muscles. These muscles move to break down your food.

It uses special liquids to help. These liquids turn food into a soft mix. This mix moves into your small gut. The stomach can grow to hold more food. It can hold about one litre of food. This helps you stay healthy and strong.

Your stomach is a vital organ. It sits between your esophagus and small intestine.

The stomach is a hollow, muscular part of your body. It can change shape when it is full. An adult stomach can hold about one litre of food. Some people have held up to 15 litres!

Inside, the stomach breaks down food using chemicals. It uses gastric acid and enzymes. Enzymes are special proteins that help digestion. Tiny parts called gastric glands make these liquids. These glands also make mucus to protect the stomach.

The stomach wall has three thick muscle layers. These layers move in a set of steps. They churn the food to break it into a soft mix. This mix is called chyme. A ring of muscle called the pyloric sphincter controls the chyme. It lets the food pass into the duodenum. The duodenum is the first part of the small intestine. This way, your body can get nutrients from your food.

The stomach is a vital organ in the digestive system. It is a hollow, muscular part of the body. It sits in the upper part of the abdomen. Specifically, it is in the left upper quadrant. The top of the stomach rests against the diaphragm.

It acts as a bridge between the esophagus and the small intestine. This organ helps turn food into energy for the body. Without it, our bodies could not process meals correctly.

Digestion in the stomach happens in a few clear steps. First, the sight and smell of food act as signals. Chewing also helps start the process. Then, the stomach enters the gastric phase. Inside, the stomach uses gastric acid and enzymes to break food down.

The stomach wall has three thick layers of muscle. These layers work together to churn the food. This movement turns food into a soft mix called chyme. Finally, a ring of muscle called the pyloric sphincter lets the chyme pass into the duodenum.

Scientists and doctors have studied the stomach for a long time. The Ancient Greeks called the stomach "gaster." This old name is why we use the word "gastric" today.

In 1896, Philip Polson introduced the term "stomach bed." This term describes the structures the stomach rests upon. These include the pancreas, the left kidney, and the spleen. Many researchers have helped us understand these parts. Their work helps doctors treat people with stomach issues.

There are many interesting facts about the stomach's size and shape. An empty stomach looks somewhat like the letter J. When it is partially full, it becomes pear-shaped.

A newborn baby's stomach can only hold about 30 millilitres. An adult stomach normally holds about one litre of food. However, some adults have held up to 15 litres in extreme cases. The stomach is also very active at a tiny level. Nearly 70% of the 20,000 protein-coding genes in human cells are expressed here.

You can think of the stomach like a powerful, stretchy mixer. It does not just hold food like a bowl. Instead, it actively works on it using special tools. It uses gastric glands to make acid and protective mucus.

These glands are found in different sections like the fundus and the pylorus. The stomach also works with your brain through nerves. These nerves tell the muscles when to move and when to secrete juices. This teamwork ensures your body gets what it needs from every meal.

The stomach is a muscular, hollow organ within the upper gastrointestinal tract. It serves as a vital component of the digestive system in humans and many animals. In medical science, terms related to this organ often use the word "gastric." This comes from "gaster," the Ancient Greek name for the stomach. The organ is located in the left upper quadrant of the abdominal cavity. Its top edge rests against the diaphragm.

Digestion in the stomach follows a specific sequence of events. It begins with the cephalic phase, where the sight and smell of food act as stimuli. This is followed by the gastric phase, which occurs once food enters the organ. Inside, the stomach performs a chemical breakdown of food. It uses secreted digestive enzymes and gastric acid to process the meal. This process turns food into a substance called chyme.

The stomach is divided into four distinct anatomical sections. The first is the cardia, which is the small region surrounding the esophageal opening. Next is the fundus, a dome-shaped area at the upper curved part. The third section is the body, also known as the corpus, which is the large central region. Finally, the pylorus connects the stomach to the duodenum. The pylorus contains the pyloric antrum, which opens into the main body.

The structure of the stomach wall is quite complex. It consists of layers including the mucosa, submucosa, muscular layer, subserosa, and serosa. The innermost layer is the gastric mucosa, a mucous membrane. Beneath this lies the submucosa, which contains fibrous connective tissue. The muscular layer is unique because it contains three layers of muscle fibers. These are the inner oblique, middle circular, and outer longitudinal layers.

Each muscular layer performs a specific job to move food. The inner oblique layer is responsible for churning and physically breaking down food. This layer is distinct because it is not found in other parts of the digestive tract. The middle circular layer helps form the pyloric sphincter. This sphincter controls the movement of chyme into the duodenum. The outer longitudinal layer uses muscular shortening to move food toward the pylorus.

Tiny gastric glands within the mucosa are essential for chemical digestion. In the fundus and body, fundic glands contain specialized cells. Parietal cells in these glands secrete hydrochloric acid and intrinsic factor. Chief cells secrete pepsinogen, which becomes the enzyme pepsin in acidic conditions. Other cells secrete a protective layer of mucus and bicarbonate. Near the pylorus, pyloric glands secrete mucus and a hormone called gastrin.

The stomach's capacity and shape change based on its contents. When empty, the organ is somewhat J-shaped. When partially full, it takes on a pear-like shape. A newborn baby's stomach can only hold about 30 millilitres. An adult stomach normally expands to hold about one litre. However, the maximum volume in adults can reach 2 to 4 litres. In extreme circumstances, volumes of up to 15 litres have been observed.

Biology shows how much activity happens within this organ. Nearly 70% of the 20,000 protein-coding genes in human cells are expressed in the stomach. Many of these proteins help create the right environment for digestion. The stomach also relies on a complex blood supply. Arteries like the left gastric and right gastroepiploic arteries provide necessary nutrients. This network ensures the stomach can maintain its intense muscular and secretory work.