The Spleen—an Amazing Organ
BUILDERS of such structures as bridges recognize the need of providing for a margin of safety. The structure must be made strong enough not only to support the maximum loads expected but to have an extra margin of safety for unexpected strains that it might have to bear. Yet, builders of bridges are not the first to consider a safety margin. God, the Creator, provided our bodies with margin-of-safety factors.
In many respects the spleen might be said to be a safety-margin organ. Until the age of two a child may well succumb to an infection if the spleen has been removed. But after that, if the spleen is removed by surgery, other parts of the body apparently take up many of its functions.
Some 1800 years ago Galen, a leading physician of those times, said that “the spleen is an organ full of mystery.” The story is told that Rudolf Virchow, leading nineteenth-century pathologist, once asked a medical student in his class what the function of the spleen is. The student stammered and said that he had known its function but had forgotten it. “What a pity!” exclaimed Virchow. “Here at last we have a fellow who knew why we have a spleen and now he has forgotten it!” And there is still much about the spleen that is not clear, as can be seen, for example, by the difference in medical opinion as to just how the blood in the spleen passes from the arteries to the veins.
Its Characteristics
It might well be said that there is no other organ in the body just like the spleen. The organ itself is insensitive to pain, being like the brain in this respect. It appears to be a gland, yet it belongs neither to the glands having ducts, for it has none, nor to those without ducts, for it produces no hormones. It has rhythmic contractions from two to five times a minute.
Where is our spleen located? In the upper part of the abdomen, just beneath the diaphragm separating the organs of the chest from those of the abdomen. It might be said to resemble a small curved hand. In adults it is about five inches long, about three inches wide and an inch to an inch and a half thick; on an average it weighs about seven ounces. It is of a purplish or deep red color and has a tough elastic outer covering or ‘capsule.’ The spleen is very adaptable, being able to alter its size to suit its work load, circumstances and even the temperature.
Just how much the spleen does can be seen to some extent from this very apt description of it: “It is a combination manufacturing shop, filtration unit, waste disposal and salvage plant, and reservoir.”—Today’s Health, November 1969.
A Manufacturing Shop
To begin with, the spleen is a manufacturing shop. Even before the third month of development of a fetus the spleen begins to work, producing white and red blood cells. However, after birth a baby’s spleen limits itself to the production of white cells called lymphocytes. But what a producer it is! It is said that the blood is sixty times richer in white cells when it leaves the spleen than when it enters it.
As a manufacturing shop the spleen also produces antibodies, tiny particles in the blood that serve to build up the body’s immunity. And the spleen produces a substance that helps the body in combating the effects of irradiation. Valuable indeed are the products ‘manufactured’ in this ‘shop.’
A Filtration Unit
The spleen is also a filtration unit. It shares with the liver in filtering out waste products in the blood, such as harmful organisms, worn-out red cells and platelets. It has a large artery seemingly all out of proportion to its size. But that it is very much needed is apparent from the fact that the body’s entire blood supply, some five to six quarts, passes through the spleen every ninety minutes.
This filtering is done largely by cells lining its blood channels. Their ability to do this baffles scientists. They tell us: “We don’t yet know what is that inherent ability in these cells that makes them so sensitive—it’s almost like a human observer, a factory inspector watching a product for defects.”
A Waste Disposal and Salvage Plant
Once having filtered out all such useless, harmful or at least imperfect elements from the blood there is the problem of getting rid of them, as well as salvaging what can be salvaged. These tasks the spleen also performs by means of certain of its cells. Red blood cells have an average life of 127 days. To keep the body properly supplied the red bone marrow must produce 2.5 million of these cells every second of every hour of both day and night. It follows that to keep the bloodstream from getting clogged, a like number, some 2.5 million worn-out cells, must be disposed of every second. Well has it been noted that the spleen (together with the liver) furnish us with “an excellent example of dynamic equilibrium.” For this reason the spleen has also been called “the graveyard of the red cells.” The cells that destroy the old and worn-out red blood cells, and which in the spleen are stationary, are called macrophages, meaning “large devourers.” The cells that attack harmful organisms are called phagocytes, meaning “cell devourers.” Toward the end of an attack by an infectious disease these cells are observed to be full of the organisms that caused the disease.
In disposing of the worn-out red cells the iron is salvaged. When the cells that destroy the worn-out cells have filled up on iron, they travel to the red bone marrow and deposit their salvaged iron there for it to be used over and over again. True it is that the spleen does not waste a single thing. Its cells are said to be more effective than those of the liver, but the liver gets more of this work done because of its having so many more of these cells.
A Reservoir
The spleen is also a reservoir. As small as it is when healthy, a spleen can expand to hold as much as a quart of blood. When we engage in strenuous exercise our spleen contracts to supply the muscles with extra blood. Likewise when there is a sudden loss of blood, as when there is a hemorrhaging or a wound, the spleen at once makes up for the loss to the extent that it can by squeezing practically all of its own blood into circulation. Similarly, when one who is used to living in a low altitude travels to a high altitude the spleen will at once send extra supplies of red corpuscles into the bloodstream; more being needed due to the scarcity of oxygen in the air. But after a time the red marrow and the heart adjust to take care of this increased burden.
In times past the spleen has often been associated with the emotions, as when one spoke of an angry person venting his spleen on someone. It appears that this point is well taken, for when a man or animal is gripped with fear or strong anger, the spleen at once contracts, sending extra blood into the circulation so as to strengthen the body for the emergency. Thus experiments have shown that the spleen of a dog accustomed to chasing cats contracts and empties its contents into the dog’s bloodstream upon his smelling a duster that has been in contact with cats or-upon hearing the meowing of a cat.
When Things Go Wrong
Not quite forty years ago a surgeon for the first time cut out the spleen of a patient suffering from hemolytic anemia, with apparently beneficial results. This operation resulted in a great increase in the investigation of the spleen. It also seemed to make temporarily fashionable the cutting out of spleens. Today, however, there is far less removing of spleens. For one thing, it was discovered that in such cases the fault is with the body’s production of defective red blood cells.
However, in certain diseased conditions doctors may recommend removing the spleen, especially when it becomes greatly enlarged. There is a case on record where the spleen increased from six ounces to twenty pounds, an increase of fiftyfold! It. was as if the woman was carrying a large baby in her abdomen! But this is rare. In fact, tumors so rarely affect the spleen that it has been described as anticancerous.
Today most operations for removing the spleen are due to severe accidents, such as those caused by auto crashes or skiing mishaps. If the capsule of the spleen gets ruptured, the blood will spill into the abdomen, and an operation may be necessary to keep the patient from bleeding to death. Or it may be damaged inside the capsule, causing it to fill up with blood until the capsule breaks, with similar fatal results possible. On the other hand, in shock, when the blood seems to disappear from circulation for apparently no reason and the patient becomes deathly pale and loses consciousness, it has been found that the spleen becomes distended with blood.
Truly the spleen serves valuable purposes. Although the body can adjust to its removal, it performs valuable services. It is indeed ‘a manufacturing shop, a filtration unit, a waste disposal and salvage plant, and a reservoir.’ How all this testifies to the wisdom of man’s Creator and underscores the words of the psalmist David that our bodies are indeed made ‘in a fear-inspiring and wonderful way’!—Ps. 139:14.