The body is constantly bombarded by toxic substances that enter it through the digestive tract, from cellular degradation or through the process of disease. The liver is an important organ that fulfils several functions, but most importantly, the liver maintains a favorable internal environment for normal cellular function.
Anatomy
The liver is in the right abdominal cavity, just below the diaphragm and on top of the stomach. It is a large, triangular shaped organ, with a dark, reddish-brown color. The liver has two lobes; each divided in to thousands of smaller lobules. Within each lobule the blood is filtered. The bile created from blood filtration diffuses into the hepatic duct that transports the bile to the small intestine and gall bladder for excretion through the feces. Bile is a substance used to carry toxic waste products from the liver, according to the University of Maryland Medical Center.
Energy
Sugar, also called glucose, is stored in the liver as a substance called glycogen. The body uses glucose to form energy; therefore, the liver acts as a fuel reservoir. The liver converts glycogen to glucose and releases the glucose into the bloodstream as required. Therefore, the liver maintains optimal blood glucose levels, as well. The hormone insulin stimulates the storage of glucose as glycogen. The conversion of glycogen to glucose is stimulated by the hormone glucagon. If glycogen levels drop, the body will conserve its glycogen stores for the organs that require glucose to function. The liver will then produce ketones, a substance produced from fat that is used instead of glucose to produce energy, according to the University of California, San Francisco.
Blood Filtration
The liver filters out most toxic waste products, drugs and other substances from the blood. An example of its filtration function is the production of bilirubin. Free heme, a component of a red blood cell, is toxic. Red blood cells die-off constantly; therefore, heme is constantly in the blood. The liver picks up the toxic heme and converts it into bilirubin. The bilirubin is transported to the intestine and excreted in the feces. In fact, the bilirubin gives the feces its brown color. Small amounts of bilirubin are also reabsorbed by the intestine and excreted through the urine produced by the kidneys. If excessive bilirubin accumulates in the extracellular fluid, the skin and sclera portion of the eye will become yellow. This is a condition known as jaundice, according to Colorado State University.
Cholesterol Production
A small amount of fat is needed for proper body function. Cholesterol is a type of fat that is adhered to a protein; therefore, creating a lipoprotein. The liver produces lipoproteins such as high-density lipoprotein, or HDL and low-density lipoprotein, or LDL. A high concentration of LDL in the blood is associated with heart disease. LDL in conjunction with other cells forms plaque within the arteries, decreasing blood flow and increasing the likelihood of blood clots that can cause heart attacks or stroke, according to the University of Washington.
Vitamin Storage
Fat soluble vitamins such as vitamins A, D, E and K are stored in the liver. Only a small quantity of such vitamins is needed for proper cellular function; therefore, the liver stores them and releases them as needed, according to Colorado State University.
