Image courtesy of Carolina Biological Supply/Access Excellence

Imagine that you are living in the year 1535, and that you don't feel well. You have had some problems with fatigue, feeling a little more tired than usual when you walked to the market and back. You tell this to your physician, and he sends you to another physician down the street, telling you there may be some problem with your circulation. When you get to the new physician, he tells you to take off your shirt and lie down on the bench. After a quick look in your mouth, he says your vital blood is probably O.K. But he's concerned that maybe your nutritive blood is not being made fast enough. Then he starts to feel around on your abdomen. He mentions that your liver is slightly enlarged and suggests that maybe you have not been eating enough green leafy vegetables or protein. Wait a minute! You have come in with problems with your circulation, and this guy is talking about your liver and the type of foods you have been eating! What is going on here? Where did this fellow learn to practice medicine anyway?

Confusion over the nature of the heart, the blood, and the role of the blood in the body had existed for centuries. Pliny the Elder, a Roman writer who lived from AD 23-79, and author of a 37-volume treatise entitled Natural History, wrote "The arteries have no sensation, for they even are without blood, nor do they all contain the breath of life; and when they are cut only the part of the body concerned is paralyzed...the veins spread underneath the whole skin, finally ending in very thin threads, and they narrow down into such an extremely minute size that the blood cannot pass through them nor can anything else but the moisture passing out from the blood in innumerable small drops which is called sweat."

A century later Galen, a Greek physician who lived in the second century AD., spent his lifetime in observation of the human body and its functioning. Galen believed and taught his students that there were two distinct types of blood. 'Nutritive blood' was thought to be made by the liver and carried through veins to the organs, where it was consumed. 'Vital blood' was thought to be made by the heart and pumped through arteries to carry the "vital spirits." Galen believed that the heart acted not to pump blood, but to suck it in from the veins. Galen also believed that blood flowed through the septum of the heart from one ventricle to the other through a system of tiny pores. He did not know that the blood left each ventricle through arteries.

Physicians, as well as citizens, of many cultures had their own beliefs concerning the nature of the heart and circulatory system. While the Greeks believed that the heart was the seat of the spirit, the Egyptians believed the heart was the center of the emotions and the intellect. The Chinese believed the heart was the center for happiness. Even our modern society continues to put emotions under the control of the heart, speaking of having a broken heart when a loved one leaves, or stealing one's heart around Valentine's Day. These beliefs continued to be taught and taken as law until an English physician named William Harvey challenged them in the late 1620's.

Next page > The Heart and the Circulatory System > William Harvey > Types of Circulatory Systems > Anatomy of the Heart > The Pulmonary and Systemic Circuits > The Blood Vessels > Circulatory Problems > Modern Cardiovascular Medicine