Your Liver Can Regenerate Itself

The ancient Greek myth of Prometheus (Review), whose liver was eaten by an eagle daily only to regrow overnight, holds a remarkable kernel of scientific truth. While our other internal organs have limited repair capabilities, the liver possesses a unique and powerful capacity to regenerate. This isn't like a lizard regrowing a perfectly shaped tail; instead, the remaining lobes of the liver expand to make up for the lost mass, a process known as compensatory hypertrophy. The liver's main cells, called hepatocytes, are typically in a resting state but are primed to respond to injury.

When a part of the liver is removed, a complex cascade of growth factors and biological signals unleashes these hepatocytes, prompting them to rapidly divide and multiply. This cellular marathon can restore the liver to its full functional mass, even if only 25% of the original organ remains. This incredible ability is the cornerstone of living donor liver transplantation. A surgeon can implant (Review) a piece of a healthy liver into a recipient, and astonishingly, the partial organ grows to a complete, functional size in both the donor and the recipient, a true feat of human biology.