While externally the human body is symmetrical, with the right and left side of the body looking so similar they could be mirror images, on the inside the organization is completely different, with bone structure and distribution that can change the size and shape of paired organs..
The muscle that pumps blood around the body and keeps us alive is situated on the left side of the body. This is also true of fish, whales, rats and other animals. According to Harvard scientists, it is our genes that determine on which sides of our bodies the organs are placed.
The left lung has to make room for the heart and for this reason it is smaller than its counterpart on the right side.
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The stomach is mostly located on the left side of the body. It is J-shaped and is the responsible for breaking down food by combining it with enzymes secreted by the lining of the stomach.
The spleen is located between the stomach and the diaphragm, on the left side of the body. It is shaped like a fist and its main function is to clean blood, combat infection and get rid of old red blood cells.
The pancreas is shaped like a pistol and most of it lies on the left hand side of the body with only a small portion extending into the right. Its main function is controlling blood sugar levels through the secretion of hormones and enzymes.