“The life of the flesh is in the blood” (Leviticus 17:11). How true this is! Man could not live without it. Blood performs many functions for man: (1) oxygenates cells; (2) removes carbon dioxide and other waste from cells; (3) transports nutrients to cells; (4) transports hormones; (5) transports and regulates heat; (6) provides defense against disease; (7) clots, preventing minor cuts from resulting in total bleed-out.
Human blood provides strong evidence for creation and intelligent design. Let’s notice…
The circulatory system is pumped by the heart. The heart is composed of four chambers. (1) The right ventricle (lower right chamber) pumps deoxygenated blood into the lungs where it picks up oxygen and gets rid of carbon dioxide. (2) The left atrium (upper left chamber) receives oxygenated blood from the lungs and pumps it into the next chamber. (3) The left ventricle (lower left chamber) pumps oxygenated blood through the body. (4) The right atrium (upper right chamber) receives the deoxygenated blood and pumps it into the right ventricle where the process starts all over. A septum (wall) keeps the oxygenated blood (left side) from mixing with deoxygenated blood (right side). Valves in the system keep the blood flowing in the proper direction. How could such a system have evolved? “Evolutionists have a difficult time explaining how the heart could have evolved to serve as a blood ‘pump’ since the heart itself requires oxygenated blood” (Brad Harrub, The Truth About Human Origin, p. 455).
The exchange of oxygen and carbon dioxide occurs in the lungs. “Alveoli are grape like bunches of very small air sacs. Each person has approximately 750 million of these. All of them together likely have a surface area which is about 25 times that of skin. Spread out flat, they would cover as much as 600 square feet. Compare a room of about 30 by 20 feet. Each alveolus is covered with a network of capillaries. These capillaries are so small that red blood cells must pass through them one cell at a time, through the very thin walls of the capillary. The blood gives up its waste, that is carbon dioxide, and takes on refreshing life-giving oxygen. Now note carefully that without this exchange, this interchange, of carbon dioxide and oxygen no human being could live more that a few moments. The body’s entire blood supply must pass through these small blood vessels every few minutes. The blood goes in one end a dark blue-black and out the other a bright cherry red, day and night this process must go on without interruption… Now we all know that one cannot live if that interchange stops longer than five minutes, and yet every evolutionist would say that for such a complexity to develop it would require not only thousands but millions of years!” (The Warren-Flew Debate, p. 116-122). Again, “the tension of oxygen is lower in the venous blood than in the alveolar air, but the venous blood has a higher tension of the carbon dioxide. The pulmonary capillaries and the air in the alveoli are separated by membranes which are so delicate as to be freely permeable to these gases – that is oxygen and carbon dioxide. The differences in the relevant pressures are favorable to a rapid inward diffusion of oxygen (from alveolar air to blood) and an outward diffusion of carbon dioxide (from blood to the alveolar air). Now notice, you have got to get oxygen into your blood and it has got to go all over your body or you will die. And you have to get the carbon dioxide out of your blood and out of the air you breathe or you will die. And that has to occur within at most a five minute period” (ibid, p. 214-216). This cries out design.
Prior to birth, things function differently. The unborn child does not breathe through the lungs, but the mother breathes for the child. The mother’s bloodstream provides the aeration for the child’s blood. Dr. Russell C. Artist explains, “until birth, the blood is diverted around the perfectly developed but not functioning lungs by a systems of bypasses… one of these is a small opening between the right auricle (part of the atrium) and the left auricle… it is called foramen ovale… The opening…the foramen ovale…is in embryonic life guarded by two flaps of tissue that permit the blood to flow through the opening. At birth, and of course instantaneously, because of certain pressure relationships, the flaps are closed never to open again… eventually new tissue grows across the opening, and in the majority of people this shortcut is completely sealed off in adult life… The other bypass in the system of circulation before birth is a short and thick vessel, covered by a tough sheet of smooth muscle. This unique blood vessel, the ductus arteriosus, is designed to carry the blood from the pulmonary directly across to the great aortic arch, thus eliminating the passage of blood through the lungs… Now we come to the muscle that contracts only once. This short-circuit, which we call ductus arteriosus, is clamped shut at the moment of birth by a ring of strongly contracting muscle… This tiny muscle remains firmly contracted until the bypassed blood vessel has withered away and then, it too degenerates and disappears, after contracting only one time! That it is absolutely essential for the two bypasses to function properly at the moment of birth… lies in the sobering fact that in the case of failure there are no second chances” (Dr. Russell C. Artist, “Fearfully and Wonderfully Made,” Gospel Advocate, January 23, 1969, quoted in Roy Deaver’s Commentary on the Book of Psalms, Vol. 2, p. 236-239). This cries out design.
“Run flat” tires are designed to provide a temporary seal to punctured tires. This enables the tire to continue to be used for a limited distance at reduced speeds.
The human blood system also has an ability to seal. “Blood clotting has to work within very narrow restrictions. When a cut occurs in an organism with a pressurized blood circulation system like ours, a clot must form quickly or the organism will bleed to death…When a cut occurs, the clot has to stop the bleeding all along the length of the cut, sealing it completely. But blood clotting must also be confined to the area of the cut or the entire blood system of the animal could solidify killing it” (Of Pandas and People: The Central Question of Biological Origins, pg. 141).
How does blood clot?
Many things must work correctly for beneficial blood clotting to occur. It takes a chain of events.
1. About 2 to 3 percent of the protein in blood plasma consists of a protein called fibrinogen. Normally, fibrinogen is dissolved in the plasma like salt is dissolved in ocean water.
2. When a cut occurs, another protein, called thrombin, slices off several small pieces from two or three pairs of protein chairs in fibrinogen. The trimmed protein is now called fibrin. Fibrin has sticky patches exposed on its surface that had been covered by the pieces that were cut off. Fibrin proteins aggregate making a protein meshwork that entraps blood cells. This forms an initial clot.
3. Thrombin initially exists in an inactive form, prothrombin. Prothrombin must be activated into thrombin before it can trim fibrinogen into fibrin. Two other proteins, called stuart factor and proaccelerin, cut off a small portion of the prothrombin to make the active thrombin.
4. Prothrombin cannot be transformed into thrombin by the presence of the stuart factor and proaccelerin without being modified. Ten specific amino acids called Glu residues must be changed to Gla residues which allows prothrombin to bind the calcium and then stick to the inside, exposed surface of the injured cell. An additional component, Vitamin K, is necessary for this modification.
5. The stuart factor must be activated for it to play its role in transforming prothrombin into thrombin. This can occur in two ways. One pathway is called the intrinsic pathway. The other is called the extrinsic pathway. The intrinsic pathway begins with trauma to the blood vessel, exposing blood to collagen. The extrinsic pathway begins with trauma to vascular walls, or extravascular tissue by exposing the blood to tissue factor.
6. What prevents the blood from completely solidifying, shutting down circulation, and leading to death?
(a) A protein called thrombomodulin lines the surface of the cells on the inside of the blood vessels. Thrombomodulin binds thrombin, making it less able to cut fibrinogen.
(b) Protein C is activated by thrombin. It is an anticoagulant.
(c) A protein called antithrombin binds to the active (but not the inactive) forms of most clotting proteins and inactivates them. Antithrombin is itself relatively inactive unless it binds to a substance called heparin. Heparin occurs inside cells and undamaged blood vessels.
7. Proteins are also involved in clot removal. They are activated at the proper time by biochemical signal.
[ Info from: (1) Michael Behe, Darwin’s Black Box, Chapter 4; (2) Of Pandas and People, Chapter 6 ]
“Why is the blood clotting system an example of intelligent design? The ordering of independent pieces into a coherent whole to accomplish a purpose which is beyond any single component of the system is characteristic of intelligence… It is like a car engine… which fails to work if the fan belt is missing, or the distributor cap, or the spark plug… When the system is lacking just one of the components… severe health problems often result. Only when all the components of the system are present and in good order does the system function properly” (Pandas and People). The cries out design.
“In humans, red blood cells are anucleated (i.e. they are devoid of nuclei)…All cells require a nucleus for reproduction and maturation even red blood cells have a nucleus during their very early stages of development…As the red blood cell matures and is ready to leave the bone marrow, it expels its nucleus… in humans, the smallest blood vessels (capillaries) often are so narrow that a nucleated red blood cell would have a difficult time passing through them… However, without the nucleus present, the red blood cell is flexible, and is able to fold over on itself. The anucleated red blood cell`s shape… can best accomplish this feat” (Brad Harrub, The Truth About Human Origin, p. 455). How could such be accomplished by blind chance? This cries out design.