Cirrhosis is a chronic liver disease marked by the progressive replacement of healthy liver tissue with scar tissue, leading to permanent damage. This process disrupts the liver’s normal structure and function, preventing it from performing its many vital roles.
Visible Characteristics
A cirrhotic liver undergoes notable macroscopic changes that can be observed directly. The size of the liver can vary, often initially enlarging before shrinking as the disease progresses due to the loss of liver cells. The surface of a cirrhotic liver characteristically appears irregular, lumpy, or nodular, sometimes described as “hub-nailed.” This nodularity results from the formation of regenerative nodules interspersed with fibrous tissue.
The color of the liver also changes, often appearing yellowish-tan, greyish, or discolored. This discoloration can be influenced by factors such as fat accumulation, which makes the liver paler, or bile stasis, which can give it a greenish tint. The texture becomes firm or hard due to the extensive presence of fibrotic scar tissue. These visible alterations reflect the underlying microscopic changes occurring within the liver.
Cellular and Tissue Changes
At a microscopic level, cirrhosis is defined by extensive fibrosis and the formation of regenerative nodules, which significantly alter the liver’s normal architecture. Fibrosis involves the excessive accumulation of collagen, a type of scar tissue, which forms bands that disrupt the liver’s intricate lobular organization. These fibrous septa can bridge between portal tracts and central veins, dissecting the liver parenchyma into distinct areas.
Within these fibrous bands, liver cells, known as hepatocytes, attempt to regenerate, forming regenerative nodules. These nodules are often encased by a fibrous pseudocapsule and lack the normal, organized structure of healthy liver tissue. The ongoing injury and death of liver cells, coupled with the impaired function of surviving cells, contribute to the liver’s declining capacity. This structural reorganization also compresses and distorts the blood vessels within the liver. The increased resistance to blood flow within the liver leads to elevated pressure in the portal vein, a condition known as portal hypertension.
Impact on Liver Function
The morphological changes characteristic of cirrhosis directly impair the liver’s ability to perform its many functions. The extensive scarring and nodule formation reduce the liver’s capacity to filter toxins from the blood, leading to a buildup of harmful substances in the body. This impaired detoxification can result in conditions like hepatic encephalopathy, where toxins affect brain function, causing confusion and concentration difficulties.
The liver’s ability to synthesize essential proteins is compromised. It produces fewer important proteins such as albumin, which helps maintain fluid balance, and clotting factors necessary for blood coagulation. Disruption of the bile ducts by scar tissue impairs the production and flow of bile, affecting digestion and the removal of waste products. This can lead to issues with fat digestion and nutrient absorption.
Metabolic regulation is also significantly affected, resulting in problems with carbohydrate, fat, and vitamin metabolism. The liver’s role in glucose regulation can be disrupted, leading to altered energy metabolism. This elevated pressure can lead to complications such as ascites, which is the accumulation of fluid in the abdomen, and varices, which are enlarged, fragile veins in the esophagus or stomach that are prone to bleeding.