What Are The Components Of Blood?

When some people think of blood they generally think of a cut or scrape that can be cleaned up and forgotten quickly. While this is the case with most folks who go through their daily lives without a major incident, there are situations in which blood is encountered in large amounts and can be the difference between life and death.

In addition, people think of blood as just one thing, an individual part of the body. In truth, blood is made up of several parts, each of which is crucial to survival for animals. The three basic components of blood are three distinct types of cells and plasma. Plasma is the liquid portion of blood that allows the cells to travel through the vessels that stretch through the body.

Major categories of blood cells are red, white and platelets. Red blood cells also go by the name erythrocytes. These cells and their color probably lead most people to think that red blood cells are “blood.” But these tiny items are just one of the essential parts of the picture. Red blood cells carry oxygen through the body, using a substance called hemoglobin, which has iron in it that gives blood much of its familiar color.

White blood cells, called leukocytes in medical use, are also a major component of blood. These crucial parts of blood can also be the difference between life and death because they are the body’s primary defense against infection. White blood cells come in three sub-types: monocytes, lymphocytes and granulocytes. These various types of white cells regulate the body’s immune system and dispose of harmful bacteria.

The third key component of blood (platelets) is smaller than red or white cells. Yet they are responsible for successful blood clotting. Basically, a wound exposes the blood to outside air and the platelets secrete fibrinogen that causes the blood to thicken and become hard. If this didn’t happen, our blood would continue to flow and we would die from blood loss.

Plasma carries the cells and a few other components such as the nutrients in our food, hormones that help the body work properly and even the waste items that will eventually be eliminated from the body. Plasma makes up slightly more than half of the blood’s volume. About 90 percent of plasma is water, with the remainder containing proteins, blood sugar (glucose), carbon dioxide that is expelled from the body during respiration etc.

Red blood cells make up a majority of the other 45 percent of blood volume. The red color comes from cells and hemoglobin that contain oxygen and iron. Animals such as humans have blood and circulatory systems that are very different from many other animals. Insects and mollusks have a different sort of liquid substance to carry the oxygen they need.

Animals such as humans have a closed circulatory system, meaning that this system is not designed to be exposed to the outside air. When it is one of the components, platelets, usually takes care of the problem through clotting. In a healthy animal the skin and blood vessel close and repair over time, restoring the blood and its essential components to working condition.

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