Circulatory System

Circulatory System

A simple definition for the circulatory system would be that it is the main transportation and cooling system for the body. Red Blood Cells have an important job in this system in that they carry all sorts of packages that are needed by all the cells in the body. Red blood cells carry oxygen and nutrients to the cells, which is needed in order for cells to survive. Besides red blood cells there are also White Blood Cells moving in the circulatory system. White Blood Cells can be considered as the paramedics, police and street cleaners of the circulatory system. Anytime we have a cold, a cut, or an infection the white blood cells go to work. From research I also came to find out that white blood cells also help cuts or wounds to heal quicker. Something I did not know was that puss which appears during an infection are actually white blood cells that are attacking the infection.

The highway system of the Circulatory System consists off a lot of one-way streets. The main routes used by the circulatory system are the veins and arteries. Veins are used to carry blood to the heart. Arteries then carry blood away from the heart. Most of the time, blood in the veins is blood where most of the oxygen and nutrients have already been delivered to the cells. This blood is called deoxygenated and is very dark red. Most of the time blood in the arteries is loaded with oxygen and nutrients and the color is very bright red. There is one artery that carries deoxygenated blood and there are some veins that carry oxygenated blood. In order to get more research on this I had to look up some information on the heart and lungs.

The heart is not hard to imagine in ones mind because it is simply a two sided, four chambered pump. The heart is mostly made of muscle and is very unique because it is the only muscle that does not become tired like other muscles. . Imagine what would happen if every 15 minutes or so ones heart becomes tired and decides to take a little break! If this were to happen it basically means that in a few moments ones circulatory system will shut down since the heart is the powerhouse of this system. Since it never rest, the heart muscle is always expanding and contracting, usually at between 60 and 100 beats per minute.

Since the heart is divided into two sections this means that each section has a specific job. The right side of the heart ...

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...ch it is then distributed to the rest of the body. The descending aorta goes behind the heart and down the center of the body. From the aorta, blood is sent off to many other arteries and arterioles (very small arteries) where it gives oxygen and nutrition to every cell in the body. At the end of the arterioles are, guess what, capillaries. The blood gives up its cargo as it passes through the capillaries and enters the venous system.

The venous system carries the blood back to the heart. The blood flows from the capillaries, to venues (very small veins), to veins. The two largest veins in the body are the superior and inferior vena cavas. The superior vena cava carries the blood from the upper part of the body to the heart. The inferior vena cava carries the blood from the lower body to the heart. . Many people believe that the blood in the veins is blue but in actuality it is not. Venous blood is really dark red or maroon in color. Veins do have a bluish appearance and this may be why people think venous blood is blue. Both the superior and inferior vena cava ends in the right atrium. The superior vena cava enters from the top and the inferior vena cava enters from the bottom.