When we “spring a leak,” why don’t we bleed to death? God has provided a wonderful substance in our blood to keep that from happening.
When I was a lad I helped my father put a shower in our bathtub. Trouble is, he didn’t use flux on the solder joints and thus we had lots of leaks! If we didn’t turn off the water and plug the holes, we would have flooded the whole house! Why doesn’t that happen with the body? When we ‘spring a leak’, why does our blood shortly stop coming out, even without a bandage? This is because of, among other things, the wonderful work of platelets. These blood cells are also made in the long bones but are half the size of a red blood cell and have no nucleus. “When you are bruised or cut, the broken blood vessels are plugged by platelets, which tend to stick to the broken edges of the vessels. Also, at these times the platelets release a substance . . . which causes contraction of the muscles of the vessel walls. This reduces the blood loss from the damaged vessels.” (Biology for Christian Schools; BJU Press, p. 621) This already smacks of design, doesn’t it?!
Platelets are also involved with the formation of blood clots. Through a series of complex chemical reactions, substances from the plasma and platelets combine to form thrombin which in turn, combined with fibrinogen from the plasma, forms fibrin, the white web in the adjacent picture (magnified several thousand times). Because of this, the blood soon stops flowing out.
Of course, clots can be dangerous if they reach the wrong places. A clot in the heart (heart attack) or brain (stroke) can be fatal. “Blood clots are gradually dissolved by chemicals in the blood as the vessel wall heals.” (ibid.) So, even the danger of their presence is taken care of by the Designer.
But the danger of blood’s inability to clot is greater. If a person lacks either sufficient platelets or the chemicals in the plasma needed for blood clotting, that person faces a serious danger from the simplest cut or bruise. Hemophilia for example, a disease carried by females but found almost exclusively in males, is caused by a lack of proteins needed for clotting. These free bleeders rarely live past their teens.
The clotting of blood at a point of damage of a blood vessel is a marvel of complexity and order! The question must be asked: if blood evolved over time, how did man or animals survive before platelets and fibron came along?
