Final answer:
The human body, according to the Doctrine of Humours, is composed of four humours: Blood, Phlegm, Yellow Bile, and Black Bile.
Step-by-step explanation:
Based on the Doctrine of Humours, which was a prevailing theory in ancient Greek and medieval medicine, the human body is composed of four humours: Blood, Phlegm, Yellow Bile, and Black Bile. These humours were thought to be linked to certain temperaments and the overall health of the body, with imbalances leading to diseases and personality differences. This theory was championed by figures such as Hippocrates and later Galen, with lasting influence throughout the Middle Ages.