The Liver
The liver is a large dark reddish-brown organ that weighs about 3 pounds, located in the upper right-hand portion of the abdominal cavity, beneath the diaphragm, and on top of the stomach, right kidney, and intestines.
There are two distinct sources that supply blood to the liver,
- Oxygenated blood flows in from the hepatic artery
- Nutrient-rich blood flows in from the hepatic portal vein
The liver holds about one pint (13 percent) of the body’s blood supply at any given moment. The liver consists of two main lobes, both of which are made up of thousands of lobules. These lobules are connected to small ducts that connect with larger ducts to ultimately form the hepatic duct. The hepatic duct transports the bile produced by the liver cells to the gallbladder and duodenum (the first part of the small intestine). The liver can lose three-quarters of its cells before it stops functioning. In addition, the liver is the only organ in the body that can regenerate itself.
The peritoneum connects the liver in 4 locations: the coronary ligament, the left and right triangular ligaments, and the falciform ligament. These connections are not true ligaments in the anatomical sense; rather, they are condensed regions of peritoneal membrane that support the liver.
- The wide coronary ligament connects the central superior portion of the liver to the diaphragm.
- Located on the lateral borders of the left and right lobes, respectively, the left and right triangular ligaments connect the superior ends of the liver to the diaphragm.
- The falciform ligament runs inferiorly from the diaphragm across the anterior edge of the liver to its inferior border. At the inferior end of the liver, the falciform ligament forms the round ligament (ligamentum teres) of the liver and connects the liver to the umbilicus. The round ligament is a remnant of the umbilical vein that carries blood into the body during fetal development.
The liver consists of 4 distinct lobes – the left, right, caudate, and quadrate lobes.
- The left and right lobes are the largest lobes and are separated by the falciform ligament. The right lobe is about 5 to 6 times larger than the tapered left lobe.
- The small caudate lobe extends from the posterior side of the right lobe and wraps around the inferior vena cava.
- The small quadrate lobe is inferior to the caudate lobe and extends from the posterior side of the right lobe and wraps around the gallbladder.
Functions of the Liver
The liver regulates most chemical levels in the blood and excretes a product called bile, which helps carry away waste products from the liver. All the blood leaving the stomach and intestines passes through the liver. The liver processes this blood and breaks down the nutrients and drugs into forms that are easier to use for the rest of the body. Some of the more well-known functions include the following:
- Production of bile, which helps carry away waste and break down fats in the small intestine during digestion
- Production of certain proteins for blood plasma
- Production of cholesterol and special proteins to help carry fats through the body
- Conversion of excess glucose into glycogen for storage (glycogen can later be converted back to glucose for energy)
- Regulation of blood levels of amino acids, which form the building blocks of proteins
- Processing of hemoglobin for use of its iron content (the liver stores iron)
- Conversion of poisonous ammonia to urea (urea is an end product of protein metabolism and is excreted in the urine)
- Clearing the blood of drugs and other poisonous substances
- Regulating blood clotting
- Resisting infections by producing immune factors and removing bacteria from the bloodstream
When the liver has broken down harmful substances, its by-products are excreted into the bile or blood. Bile by-products enter the intestine and ultimately leave the body in the form of feces. Blood by-products are filtered out by the kidneys, and leave the body in the form of urine.
The Diseases of the Liver
Important diseases of the liver include the following;
(1) Gall Stone: These are stony masses that form in the gall bladder or bile duct as a result of the production of abnormal bile by the liver. Gall stone obstruct the flow of bile and causes inflammation of the gall bladder.
(2) Viral Hepatitis: There are two types of viral hepatitis. Hepatitis A and Hepatitis B. In both cases, the virus causes inflammation and destruction of the liver cells.
(3) Cirrhosis: This is a serious liver disease in which the damaged liver cells become replaced by useless fibrous tissue. Cirrhosis may be caused by excessive drinking of alcohol over a period.
(4) Amoebic Liver Abscess: The parasitic amoeba, Entamoeba histolytica, gets into the liver from the large intestine via the hepatic-portal vein, produces an enzyme that destroys liver tissues and causes an abscess to form.
Effects of Diseases of the Liver
The effects of liver diseases are due to failure of the liver cells to function properly. The most common signs and symptoms are:
- Weakness and tiredness
- Jaundices
- Slight fever
- Tendency to bleed and bruise easily
- High blood pressure in the hepatic-portal vein in cirrhosis.
- Oedema
- Mental changes such as apathy in most liver disease.
Remedy/Treatment
The liver has a high capacity to replace damaged cells and function normally. In most cases of liver diseases, the basic treatment procedures include:
- Rest, preferably in bed
- A nutritious but controlled low fat diet
- No taking of alcoholic drinks (for the rest of the patient’s life in the of cirrhosis)
- Removal of liver disorder where possible, in the case of bile duct obstruction
- Liver transplanting
