Difference Between Abdomen and Stomach

Abdomen vs Stomach

It is not rare that some people believe the stomach and abdomen as the same thing. Hence, the differences between stomach and abdomen have a notable importance. The locations, functions, characteristics, and other features differentiate these two extremely important features of the body.


Abdomen is a main region of the body locates between the chest and pelvis. In mammals, the diaphragm separates the abdomen from the chest or the thorax, and the pelvic brim margins the other side from the pelvis. In other words, the space between the diaphragm and the pelvic brim is the abdominal cavity. Additionally, a very thin layer of cells called the peritoneum covers the abdominal cavity. In vertebrates, the abdomen is enclosed by skeletal muscles, sub-cutaneous fat layer, and externally by the skin. Most parts of the intestinal tract are located inside the abdomen. The other vital organs viz. liver, kidney, and pancreas are also located inside the abdomen. Peritoneal fluid lubricates the organs suspended in the abdominal cavity. The abdominal location and the muscle arrangement support the animal to breath properly. With all these feature, the abdomen plays a massive role in maintain life of the animal. However, in the invertebrates such as arthropods, the distinctive abdomen carries the reproductive organs mostly.


Stomach is one of the main organs located inside the abdominal cavity. It is a muscular and hollow structure, and a vital part of the alimentary system. Stomach lie between oesophagus and duodenum of the alimentary tract. It performs both mechanical and chemical digestion respectively via peristalsis and secretion of protein digesting enzymes. Stomach secretes strong acids as well, which helps for enzymatic digestion. The strong layer of muscles around the stomach helps the mechanical digestion of food through producing peristaltic movements. Usually, the stomach is a J-shaped organ, but the shape varies drastically within species. The structure in ruminants is a great variation from all other species, as the rumen has four distinct chambers. The relative location of the stomach is many animals are the same.

What is the difference between Abdomen and Stomach?

• Abdomen is a region comprising a large volume filed with the peritoneal fluid, and the stomach is a suspended organ inside the abdomen.

• Additionally, abdomen is a region, whereas stomach is an organ. In fact, stomach is the largest organ in abdomen, located in the left side of the cavity.

• Diaphragm and pelvic brim margin the abdomen anteriorly and posteriorly. The lower oesophagus and duodenum margins the stomach.

• Abdomen contains most of the intestinal parts and some other vital organs. In contrast, stomach contains gases, acids, and food.

• Stomach has an acidic interior, while abdominal cavity is not acidic, but contains peritoneal fluid.

• Initial protein digestion takes place inside the stomach, whereas rest of the chemical digestion and absorption take place in the intestine in the abdomen.