What are Hepatic Cells?
Hepatic cells, commonly known as
hepatocytes, are the main functional cells of the liver. They make up approximately 70-85% of the liver's mass. These specialized cells play a critical role in metabolic, detoxification, and synthetic activities essential for maintaining homeostasis.
Structure of Hepatocytes
Hepatocytes are polygonal in shape and possess a large, round nucleus. Their cytoplasm is rich in organelles such as
mitochondria,
endoplasmic reticulum (both smooth and rough), and
Golgi apparatus. The presence of numerous mitochondria reflects the high metabolic activity of these cells. The rough endoplasmic reticulum is involved in protein synthesis, while the smooth endoplasmic reticulum plays a role in lipid metabolism and detoxification processes.
Functions of Hepatic Cells
Hepatocytes are involved in a wide array of functions:
1. Metabolism: They are central to carbohydrate, protein, and lipid metabolism. Hepatocytes regulate blood sugar levels by storing glucose as glycogen and releasing it when needed.
2. Detoxification: They metabolize drugs, toxins, and other harmful substances, making them less harmful or converting them into excretable forms.
3. Bile Production: Hepatocytes produce bile, which is essential for the digestion and absorption of fats.
4. Synthesis of Plasma Proteins: They synthesize important proteins such as albumin, clotting factors, and various enzymes.Histological Appearance
Under the microscope, hepatocytes are arranged in plates or cords, separated by sinusoids. These sinusoids are lined with a mixture of endothelial cells and
Kupffer cells, which are liver-specific macrophages. The arrangement facilitates efficient exchange of substances between the blood and hepatocytes. Hepatocytes exhibit prominent nucleoli and a granular cytoplasm due to abundant ribosomes.
Pathological Changes in Hepatocytes
Hepatocytes can exhibit various pathological changes under different conditions:
1. Steatosis: Accumulation of fat within hepatocytes, commonly seen in conditions like alcoholic liver disease and non-alcoholic fatty liver disease.
2. Hepatitis: Inflammatory changes manifesting as swollen hepatocytes with possible necrosis.
3. Cirrhosis: Chronic injury leading to fibrosis and regenerative nodules, disrupting the normal architecture.
4. Hepatocellular Carcinoma (HCC): A primary liver cancer originating from hepatocytes, characterized by abnormal and uncontrolled cell growth.Regenerative Capacity
One remarkable feature of hepatocytes is their ability to regenerate. Following liver injury or partial hepatectomy, hepatocytes can proliferate to restore the liver's mass and function. This regenerative capacity is regulated by a complex interplay of growth factors, cytokines, and signaling pathways.Clinical Relevance
Understanding the histology of hepatic cells is crucial for diagnosing liver diseases, assessing liver function, and developing therapeutic strategies. Conditions such as
hepatitis, cirrhosis, and liver cancer can be better understood and managed through histological examination and research on hepatocyte function and pathology.
