Abdomen

The abdomen is the middle section of the body below the chest and above the pelvis.

It is also known as stomach, tummy or belly. In anatomy, the abdomen starts from the thoracic diaphragm to the pelvic brim or from the thorax to the pelvis. The abdominal cavity is the region enclosed by the abdomen. And the boundaries of this region are the abdominal wall at the front and the peritoneal surface at the back.

Organs in the Abdomen
Digestive tract which consists of stomach, small and large intestines, cecum and appendix

Accessory digestive tract organs which are the liver, pancreas and gallbladder

Urinary system which consists of kidneys and ureters (located outside peritoneal membrane)

Spleen

Human Abdomen
The ultimate function of abdomen in humans is to absorb and digest the food. This is where the alimentary or gastrointestinal tract is found which consists of the stomach and intestines including all the structures found from the mouth to anus. This body part is also vital to our immune function. With the large surface covered by the digestive tract, the body works hard on this area to prevent harmful bodies entering the blood and lymph. It is the reason why having low pH in the stomach is important as it is fatal for many harmful microorganisms. Mucus containing antibodies, enzymes in bile and saliva can also help. People may consume food and drinks like yogurt to add healthy/goo intestinal bacteria to neutralize the harmful bacteria.