Some scholars attribute the "first seed" of understanding blood flow through the lungs to the Hippocratic era.

Unlike modern medicine which views the lungs as a pair, Aristotle consistently referred to them in the ( pleumōn ). He believed: The lung is a single organ that wraps around the heart.

They identified symptoms like "Hippocratic fingers" (clubbing) and used treatments such as fumigations and specific diets for lower respiratory infections. Hellenistic Innovations

This expansion creates a "void" that draws in external air for cooling. The Hippocratic Era

Its primary movement is driven by the of the heart, which causes the lung to expand like a bellows.