Like a starfish or lizard, the liver can regenerate. A severed liver won't grow itself a whole new human, but as long as 25% of it is still there, a healthy quarter-liver can grow back to its original size.
Ancient Greek physicians talked about yellow and black bile, respectively associated with fire and earth, passion and prudence.
Chinese medicine associates the liver with the element of wood, the emotion of anger, and ying chi.
The liver may not be imbued with emotions in these anthropomorphic manners, but when it falls ill, blood won't clot, skin turns yellow, the body swells from water retention, and the brain's poisoned with ammonia.
This sleek, brown sponge separates specific compounds from blood in the body, filtering hormones, alcohol, and drugs. To the best of its abilities, it does a first pass of everything we take in, the therapeutic and toxic.
Like a moist, leather satchel, the liver also stores important molecules: glycogen; vitamins A, D, E, K, B12; iron; and copper. This hepatic purse holds the currency of life.
In addition to filtration and storage, the liver makes useful substances. Bile helps digest protein, carbs and fat, making the synthesis of clotting factors possible. Albumin keeps fluids inside the blood vessels rather than outside, in swelling skin and flesh. Angiotensin, activated by renin, raises blood pressure through narrowing blood vessels.
Once one's liver has been scarred all over by hepatitis, chronic alcoholism, or cancer, however, there's no going back. Hepatic disease is one of the worst ways to go, long & confusing, weighed down with visceral pain.
So try not to poison that slippery slab of hepatocytes too much--it has one's back in so many ways.
Image source: factor75.com
(Actual footage of me live-blogging this thing...)