Question

Explain Stomach with diagram.

Answer 1

Hint:
The stomach is a hollow muscular organ in the digestive system. It is one of the major organs of the digestive system altogether. It can expand to hold up to one liter of food. The main function of the stomach is to provide an acidic medium to digest the food material. It acts as the main site of protein digestion.

Complete answer:
The stomach lies between the esophagus of the gut and the duodenum of the small intestine. It is located in the upper left part of the abdomen, just below the lobes of the liver. The upper portion of the stomach lies close to the diagram. This results in the control of breathing concerning the stretching of muscles of the stomach.
Anatomically, the stomach is divided into three major parts. Cardiac, Fundic, and pyloric.
Cardiac – This is the part where food from the esophagus is emptied into the stomach. The stomach receives this content and it undergoes heavy physical and chemical digestive processes.
Fundic – This is the curved part of the upper left side of the stomach, that carries gastric glands known as oxyntic glands. They help in digestion by the acidification of the stomach by producing HCl and some proteolytic enzymes
Pyloric – It is the lower section of the stomach that empties the partially digested food (chyme) into the duodenum.
Apart from these three parts, the rest of the stomach is called the body of the stomach. This is where digestion happens majorly.
The bolus of food from the esophagus will trigger the release of proteases such as pepsin and HCl from the glands (The pH of the stomach during digestion is around 2.0). The stomach has a thick layer of mucus coating to prevent it from being damaged by HCl.

Note: Although most absorption occurs in the intestine, the stomach absorbs quite a lot of metabolites. Amino acids, Medication, Ethanol (from alcoholic beverages) are absorbed in the stomach. Water is also absorbed in the stomach in dehydrated conditions. A peristaltic movement of the muscles will ensure the churning of the food in the stomach. The partially digested food is then released to the intestine.