The term “hepatic” is a direct reference to the liver, serving as the medical and biological adjective for anything relating to, affecting, associated with, or supplying this organ. The word originates from the Greek term hēpar for liver, and it is used to describe a variety of structures and conditions, such as the hepatic artery or hepatic disease. Understanding the liver’s function is essential to grasping the significance of the term, as this large organ performs a vast number of tasks that sustain life.
Location and Structure of the Liver
The liver is situated in the upper right quadrant of the abdominal cavity, nestled beneath the diaphragm and mostly protected by the lower rib cage. It is the largest internal organ in the human body, typically weighing between 3 and 3.5 pounds in an adult.
The liver is anatomically divided into two main sections, the larger right lobe and the smaller left lobe, which are separated by the falciform ligament. Internally, these lobes are further organized into thousands of microscopic units called lobules, which are the functional building blocks of the organ. The liver receives a dual blood supply from two major vessels.
The hepatic artery delivers oxygen-rich blood to nourish the liver tissue. Meanwhile, the hepatic portal vein transports blood rich in digested nutrients, as well as toxins and waste products, directly from the gastrointestinal tract. This arrangement ensures that all substances absorbed from the intestines are immediately filtered and processed by the liver before being distributed to the rest of the body.
Essential Functions of the Liver
The liver’s functions can be broadly categorized into metabolism, detoxification, and production of essential substances, all of which are managed by specialized cells called hepatocytes.
In terms of metabolism, the liver acts as the body’s central processing plant for all major nutrients. It manages carbohydrate metabolism by storing excess glucose as glycogen, which can be broken down and released into the bloodstream when energy is needed, thereby regulating blood sugar levels. For fat metabolism, the liver synthesizes cholesterol and lipoproteins for transport throughout the body, and it also breaks down fatty acids to produce energy. Protein metabolism involves synthesizing non-essential amino acids and converting harmful ammonia into urea, which is then safely excreted by the kidneys.
The detoxification process is a constant and necessary function, as the liver filters the blood to neutralize harmful substances. It uses enzyme systems to chemically alter drugs, alcohol, and metabolic waste products, converting them into water-soluble compounds. These less harmful compounds can then be eliminated from the body via the urine or through the bile.
The liver is a major production center, synthesizing several proteins and biochemicals necessary for health. It produces albumin, the most common protein in blood serum, which helps maintain fluid balance and transports hormones and drugs. Crucially, the liver synthesizes most of the coagulation factors, such as prothrombin and fibrinogen, which are required for blood clotting. It also produces bile, a fluid that aids in the digestion and absorption of fats and fat-soluble vitamins in the small intestine.
Common Hepatic Conditions
When the liver’s function is compromised, it results in a variety of hepatic conditions. One of the most common issues is Hepatitis, which is defined as inflammation of the liver tissue. Viral infections, such as Hepatitis A, B, and C, are frequent causes, although inflammation can also be triggered by alcohol abuse or autoimmune disorders.
Another widespread concern is Fatty Liver Disease, which occurs when excessive fat builds up within the liver cells. This condition is divided into two main categories: alcoholic fatty liver disease, caused by heavy alcohol use, and nonalcoholic fatty liver disease (NAFLD), which is often linked to obesity and metabolic syndrome.
The progression of liver damage eventually leads to Cirrhosis, a condition where healthy liver tissue is replaced by scar tissue, resulting in a firm, nodular organ. This scarring permanently impairs the liver’s ability to perform its metabolic and filtering functions. Cirrhosis can lead to liver failure and is a major indication for a liver transplant.