What is the structure of the liver?
The liver is a vital organ located in the upper right quadrant of the abdominal cavity, just below the diaphragm. It is the largest internal organ in the human body, weighing approximately 1.5 to 1.6 kilograms in adults. The liver’s primary function is to process nutrients from the digestive system, detoxify harmful substances, and produce bile, which aids in the digestion and absorption of fats. Understanding the structure of the liver is crucial for comprehending its functions and the potential health issues that may arise. In this article, we will explore the various components and layers that make up the liver’s structure.
The liver is divided into two main lobes: the right lobe and the left lobe. The right lobe is larger and accounts for about 80% of the liver’s total weight. The left lobe is smaller and is located on the left side of the liver, adjacent to the stomach. The lobes are further divided into segments, which are numbered from 1 to 8. These segments are defined by the portal triads, which consist of the hepatic artery, portal vein, and bile duct.
The liver is surrounded by a protective capsule called the Glisson’s capsule. This capsule is composed of dense connective tissue and encloses the liver’s outer surface. The Glisson’s capsule also gives rise to the ligaments that attach the liver to the surrounding structures, such as the diaphragm and the abdominal wall.
The liver’s parenchyma, or functional tissue, is composed of hepatocytes, which are the liver’s main cells. Hepatocytes are arranged in cords, or hepatic plates, that run parallel to the surface of the liver. These cords are separated by sinusoids, which are small blood vessels that allow for the exchange of nutrients, oxygen, and waste products between the hepatocytes and the blood.
The liver’s blood supply is derived from two sources: the hepatic artery and the portal vein. The hepatic artery carries oxygenated blood from the heart to the liver, while the portal vein carries nutrient-rich blood from the digestive system. The hepatic artery and portal vein enter the liver through the porta hepatis, a triangular opening on the liver’s surface.
The liver is also equipped with a network of bile ducts that transport bile to the gallbladder and, eventually, to the small intestine. Bile is produced by hepatocytes and helps in the digestion and absorption of fats. The bile ducts are arranged in a hierarchical structure, starting with the small bile ducts that drain from the sinusoids, followed by the larger bile ducts that merge to form the right and left hepatic ducts, and finally, the common hepatic duct, which joins with the cystic duct to form the common bile duct.
In conclusion, the liver’s structure is complex and multifaceted, with various components working together to ensure its proper functioning. Understanding the liver’s structure is essential for diagnosing and treating liver diseases, as well as for maintaining overall health.
