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.

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.