Question

My textbook says that the hepatic lobule is the structural and functional unit of the liver. I'm confused as to why don't call hepatocytes the structural and functional unit of the liver instead, as they are the actual units secreting phospholipids, bilirubin and other components of the bile juice.

I framed this answer based on my understanding, please verify if I'm right or not and do suggest improvements-
"Properties of the hepatic lobule are not present in hepatocytes, they arise due to the interaction of hepatocytes. Therefore, hepatocytes on their own, cannot be termed as a functional and structural unit of the liver"

Answer 1

Although hepatocytes are vital liver cells, the hepatic lobule is considered the structural and functional unit of the liver because it comprises hepatocytes, bile canaliculi, and hepatic sinusoids, which collectively ensure efficient liver function.

Step-by-step explanation:

Your understanding about the hepatic lobule and hepatocytes is on the right track. While hepatocytes are indeed the main cell type, comprising around 80% of liver volume and responsible for a multitude of functions including secretion of bile components, they do not act alone. Instead, hepatocytes are part of a larger structure, the hepatic lobule, which can be considered the true functional unit of the liver.

Hepatic lobules are made up of hepatocytes, but also include bile canaliculi and hepatic sinusoids. These additional components are critical for the proper functioning of hepatocytes and for the intricate process of managing substances absorbed from the digestive system. Hepatic lobules ensure that hepatocytes are correctly positioned to interact with both oxygen-rich blood from hepatic arteries and nutrient-rich blood from the portal vein. Additionally, the arrangement allows for efficient blood flow through fenestrated capillaries, facilitating the processing and detoxification of substances, and also for the collection and expulsion of bile through the bile canaliculi.

The complex functionality of the liver, including its capability to produce and secrete bile, emulsify fats, store nutrients, and process toxins and waste materials, all arise from the collaborative work within the hepatic lobule. Hepatocytes are indispensable, but it is the organized structure of the lobule that makes these functions possible and efficient.