Who were Hippocrates and Galen?

Hippocrates is often referred to as the Father of Medicine, as he is the oldest Greek doctor whose writings we can access.

Galen is the most famous Greek doctor of the ancient past. This is probably because his treatises on digestion dominated medicine for fourteen centuries.

How was digestion first illustrated?

In the 2nd century, Galen described digestion as a form of cooking food.

As he understood it, chewing physically prepares food and then the stomach cooks it. The lobes of the liver facilitate this process by surrounding the stomach to heat it.

Food then passes from the intestine into the liver where it is turned into blood. This then passes through the veins to supply the various parts of the body.