Anatomy And Physiology

The spleen and how it functions

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"The spleen and how it functions"
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The spleen is one of those odd organs found in people which is often overlooked. It has an important role to play in keeping you healthy, but because it is not strictly necessary to live, the spleen often gets overshadowed by the heart, liver and even the oddly shaped pancreas. It should be noted that people who have their spleen removed are more susceptible to certain infections.

The spleen can be found on the left side of your abdomen, just below the diaphragm (which is the internal muscle that aids in breathing), and approximately behind your stomach. It is normally above the left kidney and large intestine. It typically weighs about 5 ounces and is about three to five inches long, but there can be significant variation in size from person to person.

The spleen is roughly ovoid in shape. It is made up of numerous areas of lymphatic tissue which surround arteries and veins. If you were to take a cross section of the spleen, you would find that it is separated in to two distinct types of tissue. They are called red pulp and white pulp. I'll give you one guess how they got those names.

Red and white pulp have different functions. Red pulp contains blood filled sinuses (a fancy name for spaces). The primary function if red pulp is to act as a mechanical filter, removing old red blood cells from general circulation.

White pulp contains many B and T type lymphocytes. These cells are vital to the functioning of the immune system. Naturally, this means that the white pulp plays an important role in fighting infections within the body.

The spleen is also a secondary manufacturer of red blood cells. In adults most red blood cells are made in the long bones such as your femur, but the spleen is a important producer of red blood cells in a fetus. Once the long bones are fully developed, the spleen's production of red blood cells becomes insignificant.

There are times when a spleen must be removed. Various types of infections, trauma, certain cancers, and even genetic diseases are all reasons the spleen may have to be removed. A person can live without a spleen, but they will be at increased risk for getting infections, as all the immune system cells found in the white pulp will be harder for your body to make (they are made in other places as well, just not as easily).

Interestingly, people who suffer from sickle cell anemia will often become what is called, "asplenic". This is caused by the oddly shaped red blood cells found in sickle cell patients getting jammed in the small arteries and veins of the spleen causing it not to work. While these people still technically have a spleen, it ceases to function properly, effectively putting them in a state where they may as well not have a spleen at all. This is known to doctors as an "autosplenectomy".

More about this author: Erich Rosenberger M.D.

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