The word circulation may have two distinct meanings. It may portray the concept of the heart delivering oxygen blood to human cells or it may portray the concept of traffic flowing. These concepts of circulation may be quite different but they are similar in many ways. Just think of the heart as an effective traffic light and the blood as a flow of vehicles being ordered to reach important destination. However, allow the roadways to be blocked because of a malfunction and a potentially dangerous ''blood clot '' will form, something very similar to a traffic jam.
Circulation is taken care of by the cardiovascular system, whose components are the heart, blood vessels, capillaries and of course the blood. During circulation, important nutrients along with oxygen are delivered to the body cells and tissues while the waste products produced by the body are effectively removed. This created two different routs: oxygen rich, nutrient blood being delivered from the lungs and heart to the body cells and carbon dioxide, waste rich blood being delivered from the cells to the kidney and lungs where they are excreted.
Therefore, imagine, a dark blue garbage disposal truck that carries waste from the cells and dumps them to lungs and kidneys where they are disposed of. The route taken by this truck is one way and it called the ''pulmonary loop''. This loop is found on the right side of the heart.
Now, imagine a bright red produce delivery truck departing with fruits and veggies and carrying them to the cells. The route taken by this truck is as well, one way and it is called the ''systemic loop''. This loop is found in the left side of the heart. The truck then continues its journey through highways known as veins.
Both trucks are effectively ordered to move by the heart, the main traffic light of the body which permits the flowing of traffic through its contractions. The valves placed at the exits of these routes ensure that the roadways remain only one way.
Let's take a closer look now at the specific routes each truck takes.
Route A Dark Blue Waste Disposal Truck From Body to Lungs
The dark blue waste disposal truck which got previously loaded with waste from the body is directed towards the heart by entering the right atrium and right ventricle, here it enters the lungs through the pulmonary arteries where it unloads and refreshes its blood. This is a transit area: the dark blue truck has finished its journey and is now replaced by the bright red produce truck.
Route B Bright Red Produce Truck From Lungs to BodyThe bright red produce truck departs from the lungs and is directed towards the pulmonary veins into the left atrium, then it is pushed through the mitral valve into the left ventricle, pushed through the aortic valve, through the aorta and finally to the body in order to allow the hungry cells to feast on the nutrients delivered. At this point the bright red produce truck stops at a transit area after feeding tissues and cells. This is where the dark blue waste disposal truck takes over until it reaches the lungs. The routes are repeated over and over during the day, creating circulation. The commanding center of the circulatory center is the heart. Again compared to a triffic light, when the traffic light turns ''green'' the truck is pushed out the intersection (systolic contraction) whereas when the traffic light turns red, the truck awaits at the intersection (diastolic contractions). In other words, systolic contractions push blood out, whereas diastolic contractions allow the blood to fill the heart. Valves open and close accordingly acting as gates, ensuring only one way routes are taken.
When trucks are overflowing with harmful substances such as fatty deposits these may be left behind and ultimately block the roadway. When this happens a traffic jam takes place and a ''blood clot'' will form in the important coronary arteries. Such traffic jams stops the flow of traffic and the truck delivering healthy nutrients may be unable to pass by as before.It important to note that the heart does not feed on the nutrients trucks deliver through the veins, rather the heart has its own set of express limousines that travel through arteries which deliver it with oxygen and nutrients. Deprived of these nutrients, the heart will become ''ischemic'' meaning it will suffer from lack of oxygen. Ultimately, if deprived by oxygen the heart may suffer an infarction, which is basically a heart attack.
The human body is an amazing machine. The heart, (on the contrary of real traffic lights which turn green every 60 seconds) successfully and efficiently delivers blood about 72 times per minute, or better 100,000 times a day for all our entire life. Therefore, treat your heart well, eat healthy, avoid bad fats and exercise so your heart will stay healthy. Refrain from treating your heart well, and just as a traffic light, the heart may stall , traffic jams may form and there will be overwhelming chaos that may cost your life.