The stomach and the organs surrounding it comprise a very interesting and important area of the human body. This, of course, is where a large part of digestion of the food we eat takes place, providing the rest of the body with macro- and micronutrients needed to survive and for optimal cellular functioning.
In this article, we have an anatomy and picture of the stomach area to highlight this important organ and understand its role in the digestive system as a whole.
Structure and function of the stomach
The stomach is a hollow, muscular and somewhat bean-shaped organ that is located slightly left of center in the upper-left quadrant of the abdominal cavity in humans. In adults, the average volume of an empty stomach is about 75 mL, although it can expand to hold about 1 L of food. It is attached to the esophagus (superior to the stomach) and the duodenum of the small intestine (medial/inferior to the stomach). At each of these junctions, the entry and exit of contents into and out of the stomach is regulated by a sphincter muscle (the esophageal sphincter and pyloric sphincter, respectively).
The stomach carries out the second phase of digestion by secreting proteases (protein digesting enzymes) and strong acid known as gastric acid (hydrochloric acid). A layer of mucus protects the stomach from its own acid secretions. Contractions of the smooth muscle in the stomach wall churn its contents and help break it down. A few substances are absorbed into the bloodstream through the wall of the stomach (most nutrients are absorbed later in the small intestine); these include caffeine, some medications like aspirin, a small amount of ethyl alcohol (from alcoholic beverages) and amino acids.
Anatomy of the stomach area
Several key organs are packed closely with the stomach in the abdominal cavity, including the liver, whose smaller left lobe is located superior to the stomach and whose large right lobe occupies the same space in the upper-right quadrant as the stomach and left lobe combined. The gallbladder is attached to the stomach at the duodenum to neutralize the acidity of the partially digested food before it enters the small intestine. The pancreas is found behind the stomach (posterior) and the spleen is located lateral to the stomach. Although they are not directly attached, the transverse portion of the colon (large intestine) passes directly under the stomach as it crosses the abdominal cavity.