It takes about 60 seconds for all the blood in your body to complete its journey. It travels from your heart to your extremities and returns, there and back again. Blood moves with the rapid current of the great arterial rivers and through the smallest capillary creeks. William Harvey first noticed circulation (1628) through the heart into arteries and veins; however, he could not see how they connected since he did not have a microscope. The man who first described this was Anton van Leeuwenhoek about 46 years later (1674). Then, J. J. Lister and Thomas Hodgkin described the rouleaux formation or stacking of RBCs through a capillary bed. All of these men mentioned above were committed Christians.
Three hundred years ago (1719), Leeuwenhoek was providing his most detailed account of red corpuscles and capillary circulation. He also provided an accurate measurement of 0.003 inches (actual: 6.2–8.2 µm) for human blood cells and described many different types in animal cells. This was about 45 years after he first described them as a young man (1674).
The human body produces two million blood cells deep in its bone marrow per second and pumps 1500–2000 gallons per day. Once formed, those red blood cells (RBCs) move into the bloodstream with white blood cells and platelets, all circulating through 60,000 miles of arteries, veins, and capillaries in the human body. Leeuwenhoek described the connections between arteries and veins as capillaries and demonstrated what Harvey could only postulate.
BLOOD REVEALS MUCH ABOUT THE MAJESTY OF OUR CREATOR AND MASTER CRAFTSMAN, IRREDUCIBLE COMPLEXITY, AND THE HEALTH OR DISEASE STATE OF THE HUMAN BODY.
Knowledge of the blood and circulatory system gives us insight into spiritual, biological, and clinical applications. Blood reveals much about the majesty of our Creator and Master Craftsman, irreducible complexity, and the health or disease state of the human body. Capillaries are the smallest blood vessels through which blood cells can move through in single file. This blood vessel network knitted with lymphatic capillaries shows an interwoven complexity, thus revealing the fearfully and wonderfully made design of our body (Gillen, 2009). In this article, we also show a biblical worldview and notable Christians who expounded the biblical concept that “Life is in the Blood.”
For the life of the flesh is in the blood. (Leviticus 17:11)
Gillen, Alan L. and Conrad, Jason, "Life Is in the Blood" (2019). Faculty Publications and Presentations. 148.