You get a cut or scrape on your skin, and what happens? Except for applying antibiotic or a bandage, you probably think little of it. It heals, and life goes on. But the skin healing process is something we should not take for granted.
Our bodies perform a complex healing process for even a small wound. Granulation tissue consists of new connective tissue and microscopic blood vessels. Your body generates granulation tissue from the base of the wound growing until it closes the wound. It may be light red to dark pink because of the new blood capillaries, and it’s usually moist and bumpy, or “granular.”
Cells surrounding the wound secrete molecules called extracellular matrix (ECM) to provide structural support. Cells called fibroblasts secrete collagen, the main structural protein of connective tissue. Collagen is resistant to bacteria, so it helps prevent infection while promoting healing. Fibroblasts are stem cells, meaning that they can morph into various kinds of cells as needed for the part of the body that’s being healed.
Epidermal growth factor (EGF) is a protein that stimulates cell growth. It’s found in blood plasma, and blood is supplied to the new tissue through the new capillaries. An interesting sidenote is that EGF is also found in the saliva of all mammals. When an animal licks its wounds, it’s not just cleaning the area, it’s also helping to promote the healing of the wound.
This is a greatly oversimplied explanation of the skin healing process, but it shows a glimpse of a very complex system that we can’t believe was an accident. Even before the healing begins, another complex process causes the blood to clot. We think that the ability of our bodies to heal is another example engineering design by the Master Designer.
A couple of days ago, I accidentally sliced the tip of my finger with a sharp knife. It bled a lot for a while, but in a short time, the bleeding stopped. The bleeding probably helped cleanse any debris from the wound, but I didn’t want the bleeding to continue. If our blood did not clot, we could bleed to death from even a small injury. Blood clotting design, or coagulation, is a very complicated process that scientists have studied for years.
The process begins when a puncture to your skin injures a blood vessel exposing blood platelets to the collagen beyond the blood vessel’s lining. The platelets immediately bind to the collagen and each other, forming a temporary plug. This starts a whole series of complex chemical reactions involving proteins and enzymes called clotting factors.
A cascading series of a dozen steps must take place for coagulation to complete. The result is the creation of fibrin strands which strengthen the platelet plug and stop the bleeding. If any single factor of the clotting process is missing, the clot does not form, and the bleeding continues.
Hemophilia is a genetic defect that omits a clotting factor. It disrupts the process of blood clotting design such that people with hemophilia may bleed uncontrollably from even a small wound. This is an extremely simplified summary of the coagulation process involving a dozen factors requiring specific proteins and enzymes that must happen in a particular order. For more details, click HERE.
Without blood clotting, humans and other mammals could not have survived. All of the clotting factors had to be present at the beginning of mammal and human life, meaning that the coagulation process could not develop gradually by chance. The fact that our blood clots when we are injured is another evidence of design by an intelligent Creator.