Hepatocytes

Hepatocytes are the fundamental and essential cells that make up the liver tissue. Thus, they form the parenchyma of this organ. They are cuboid, secretory, epithelial cells, which are derived from the foregut endoderm. They are arranged in anastomosing plates and cords. As secretory cells, the hepatocytes produce exocrine and endocrine secretion.

The exocrine part of the parenchymal liver cells discharge bile into tiny intercellular channels called canaliculi, while the endocrine portion secretes plasma proteins, glucose, and lipoproteins, which are released into the bloodstream. Thus, the hepatocytes have parts of their surface bordering on bile canaliculi, while the other parts border on wide venous blood vessels, which are known as hepatic sinusoids.

Hepatocytes Organelles - Functions

Mitochondrion- Each liver parenchyma cell has hundreds of mitochondria, which are evenly distributed throughout its cytoplasm. Not only does this organelle produce adenosine triphosphate (ATP) necessary for mitochondrial synthesizing activities, but also ketone bodies and glucose from fatty acid and glycerol during fasting, very low carbohydrate consumption, and type-I diabetes hyperglycemia.

Rough endoplasmic reticulum- It is found in abundance in the hepatocytes, enabling the liver cells to perform the function of synthesizing and secreting all serum proteins, such as serum albumin, microglobulins, serum lipoproteins, and transferrin.

Smooth endoplasmic reticulum- It contains enzymes involved in cholesterol biosynthesis. These enzymes are also involved in the breaking down of glycogen, as well as in drug and poison detoxification.

Golgi apparatus- This organelle is involved in glycosylation, which is the addition of saccharides (sugars) to proteins and lipids to form glycoproteins and glycolipids.

Lysosomes- Their primary functions are to destroy worn cellular components. They are also crucial for iron recovery and turnover of glycogen stores.

Above, scanning electron micrograph of fractured liver parenchymal cells (H), showing a sinusoid (S) and bile canaliculi (BC). (Courtesy of Dr. E.N. Albert - Department of Anatomy, George Washington University).