Question

The lost portion of the liver is regenerated by:
A. Reparative regeneration
B. Compensatory hypertrophy
C. Heteromorphic regeneration
D. None of the above

Answer 1

Hint: Liver regeneration is compensatory because original shape of the liver is not regained.

Complete answer: In Biological sciences, regeneration is referred to as the process of renewal, restoration, and tissue regrowth after disturbance or damage of cells, organs or tissues of an organism.
1. Regeneration is of three types: morphallaxis, epimorphosis and compensatory regeneration.
2. In humans, the liver is the only visceral organ having the capacity to regenerate. Liver regeneration is a process by which the liver can replace its lost tissue with growth of the remaining liver tissue. The liver can undergo regeneration in two events: after partial hepatectomy and upon being damaged by toxins or infection of microbes.
3. The liver can regenerate after surgery or chemical injury. Approximately 51% of the original liver mass can be regenerated back to its actual size.
4. In mammals, the process of liver regeneration follows a compensatory regeneration pattern. It is because only the liver mass is replaced, but not the original shape of the liver.
5. Hepatocytes (liver cells) are responsible for the ability of liver's regeneration.
6. The hepatocytes act as stem cells which can re-form the liver tissue. Compensatory hypertrophy occurs to regenerate the lost portion of dissected liver. Here, the re-growth occurs as a result of increased cell size.

So, the correct option is B. compensatory hypertrophy.

Note: The word ‘hepatic’ is related with liver and hence liver regeneration is also known as hepatic regeneration