Several organs are located on the left side of the body, including the left eye, the left ear, the left lung, the spleen, the left kidney, the bladder, the adrenal gland, the pancreas, the left ureter, the left Fallopian tube and the left ovary. A handful of organs straddle both sides of the body, such as the skin, the nose, the mouth, the brain, the heart, the stomach, the small intestine, the large intestine and the rectum. In males, the left testicle is also considered a left side organ.
Many left organs are mirrors, which means they have a counterpart on the other side of the body as well. These include the lungs, kidneys, ureter, Fallopian tubes and ovaries. In males, the testicles are also mirror organs. Approximately one in every 10,000 people is born with a condition called situs inversus, in which the organs are flipped; the left organs are located on the right and the right organs are on the left.
Each organ is part of a larger body system, each with a different function. The nervous system is essentially mission control for the human body, sending messages throughout the body that tell it what to do. The brain is a major organ of the nervous system. The heart is part of the cardiovascular system, which pumps blood throughout the body. Blood contains oxygen, which is vital to human survival. This is why humans die if the cardiovascular system permanently ceases to pump blood. The spleen is part of the lymphatic system. The lymphatic system maintains the immune system, which fights disease and illness. The mouth, stomach, large intestine, small intestine, rectum and pancreas are the left-side organs of the digestive system, which breaks down food and dispenses food throughout the body. The bladder, ureter and kidney are part the system that dispenses waste from the body. This system is called the urinary system. The respiratory system, which helps humans breathe, encompasses the left lung and nose. The left testicle, left ovary and left Fallopian tube are part of the reproductive system, which consists of the organs that help humans reproduce.