Amazing Facts

Red blood cell functions

Red blood cells function by carrying oxygen to
every part of the body, and then carrying carbon dioxide back to the
Red blood cells are very well designed to perform this important job.
First, they are packed full of hemoglobin, which is an iron-bearing
protein that transports oxygen to other cells. Interestingly, red blood
cells have no nuclei, a feature which makes even more room for
hemoglobin. Red blood cells are the only cells in the body that do not
have a nucleus.

Second, they are shaped like disks. This shape
greatly increases
their surface area compared with a sphere of the same volume. The large
surface area is important because it improves the efficiency of oxygen
transfer between hemoglobin and the tissues where the oxygen is needed.
Red blood cells are formed in the bone marrow, where special cells
called stem cells divide repeatedly, then lose most of their internal
parts before they are released into the blood. Red blood cells have an
average life span of about 120 days. After this, they tend to become
misshapen and they are removed from the circulation system by the
spleen. A typical human body makes about 2.5 million red blood cells
every second, or about 200 billion every day!

Red cells normally comprise about 40% of the
volume. When doctors measure this number, it is called the hematocrit.
Sometimes the number of red blood cells drops too low. This condition
is called anemia. Generally, anemia results either because too few red
blood cells are being made, or because they are being destroyed
prematurely. The most common cause for underproduction of red blood
cells is iron deficiency. Iron is a necessary component of hemoglobin,
so iron deficiency results in inadequate formation of new red blood

Related Tags: Blood  Human  Body  
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