2023-09-08 by Khushi Goel
Why can only the liver regenerate?
Liver is an important organ in our body as it is the largest gland inside us. It produces bile juice which plays a crucial role in the digestion of food. The liver can be divided into three subsections called ‘lobules’. If you were to observe a small section of the liver under a microscope you’ll observe many hexagonal cells known as “hepatocytes”. Hepatocytes are the most abundant and largest cells in the liver.
These cells perform specific functions and remain in a non-dividing stage (i.e. they do not grow and divide to produce new cells) under normal conditions. They remain in a state of rest called the ‘quiescent state’.
Whenever there is an injury or damage to the liver tissue, the hepatocytes receive a signal and start dividing to heal the damaged part of the liver. This is a unique property which is not observed in other organs. We often call this, ‘Liver Regeneration’.
To be able to divide, the liver cells need to ‘wake up’ or as scientists say, they need to get activated. The process of liver regeneration happens in three phases:
- initiation phase (hepatocytes receive signal to start dividing),
- proliferation phase (hepatocytes divide and grow in number) and
- termination phase (the cells stop dividing once the normal size & structure of the liver is retained).
The liver can regrow to its original size if approximately 2/3rd of the liver is removed or damaged. If the damage is in more than two-third part of the liver, it cannot recover on its own. In such cases, the patient needs a liver transplant.
There is one more organ which regrows almost daily. Can you name it? (Hint: It covers your entire body!)
References:
- https://kids.frontiersin.org/articles/10.3389/frym.2017.00038#:~:text=After%20a%20wound%20or%20other,%2C%20that%20is%2C%20a%20transplant.
- https://theconversation.com/curious-kids-why-can-some-organs-regenerate-while-others-cant-128217#:~:text=Our%20livers%20are%20very%20good,hepatocytes%20work%20like%20stem%20cells.