Blog

by Steve Risner

The heart sits as the center piece of our circulatory system. This pump weighs in around ½ pound and will circulate blood through your body starting less than 2 months after conception until you pass into eternity—about 75 times per minute, or 3 billion times in the average lifespan. The circulatory system has more than just a heart, however. It consists of the heart, blood vessels and capillaries, and the blood itself. But critical to this system are other very important organs like the lungs, kidneys, liver, and spleen to mention some of the big ones. Fifteen to twenty percent of your blood volume (or about 2/3 of a quart) will circulate through your brain at any given minute. It will take the average blood cell about 20 seconds to circulate throughout the body. By the end of its life, it will have travelled about a quarter million times around the body! And the heart has more than one fail safe system for making sure it gets the stimulation it needs to beat. There are nerves from the brain, the sinoatrial node, the Bundle of His and Purkinje fibers that all work to make sure the heart does not stop.

The circulatory system is vital for fighting diseases and maintaining homeostasis (proper temperature and pH balance). The system's main function is to transport blood, nutrients, gases, and hormones to and from the cells throughout the body. It also allows communication to take place from one body part to another. This blood will travel, on average, through 60,000 miles of arteries, capillaries, and veins or more than twice around the earth.

Red blood cells are unique cells in the human body in that they do not contain a nucleus and have few organelles. This gives them the almost donut like appearance we’ve all seen in pictures. This unique characteristic allows them to fit through the capillaries, which are nearly exactly the same size as the blood cells—about 1/3000 of an inch or a tenth of the diameter of a hair. In some areas, the capillaries are smaller than the red blood cells, so the blood cells actually deform momentarily to work their way through these passages. Without them, we would die. But there is a lot more to your blood than just red blood cells.

First, there are different types of blood in the human body—arterial and venous. The former is rich in oxygen and carries nutrients away from the heart. The latter carries waste products, primarily carbon dioxide, back to the heart. Within our blood is a very long recipe of ingredients that allow us to live. There are, obviously, red blood cells. But there are also white blood cells which are one of our immune system’s greatest weapons. There are several types of white blood cells, many of which are phagocytic (they eat stuff). There is even one called a natural killer cell which, as the name implies, kills cells of the body that do not have the proper identification. Our white blood cells die daily in the battle to keep us infection free. The nasty material we find in pockets called pus is actually an accumulation of dead white blood cells that have fought the good fight for our good. Without them, we would die.

There is yet another type of cell commonly found in our blood called thrombocytes or platelets. They are involved in blood clotting so we don’t bleed to death every time our skin is broken. Without them, we would die.

There are also other things in our blood, including a great deal of water. 92% of the plasma (the part of the blood that is not blood cells) is water. The other 8% is mostly protein and minerals. Within this list of proteins are primarily albumin and clotting factors. Albumin is essential for maintaining the proper pressure in our system to pass nutrients and waste products back and forth. Without it, we would die.

The Bible tells us that the “life is in the blood” in Leviticus 17:11. It also tells that without the shedding of blood, there is no forgiveness. Blood is complex and very important physically and spiritually.

Truly, the extremely complex system consisting of a pump, an extensive exchange system, and the plumbing to get the nutrient rich fluid we call blood through our bodies is something we could not live without and we have a lot to learn about it. Some may try to say that this complex and highly interdependent system arose out of mindless accidental genetic mistakes. Could this be more absurd? If any of these parts are not in place correctly, we would not be alive. How did such an interdependent system evolve over time? We know the truth is that God created this amazing system perfectly and in place. There really is no other option that makes any sense at all.