Processes of the heart and lungs

17 03 2010

I was initially struggling with grasping this process until I started viewing the heart as two separate parts in one unit – the deoxygenated side and the oxygenated side, or the interatrial and interventricular, respectively (Fremgen et al 134).  As this is an ongoing, circular process it has no beginning, nor end, so I will begin describing the process from the point where the deoxygenated blood arrives at the heart from the body.

The process begins as the blood travels through the body, dispersing the oxygen from its cells and then returns through the two vena cava veins that import deoxygenated blood to the heart (Cardiovascular Consultants).  The deoxygenated blood arrives at the heart, specifically into the right atrium, which is one of the two upper chambers of the heart muscle.  The atrium fills with blood and the chamber below the right atrium, called the right ventricle, relaxes.  Once the atrium has filled, it expels its contents into the emptied right ventricle through a contraction.  Now that the right ventricle is filled, it pushes the blood into the lungs, emptying once more while the atrium fills (Lujan et al).  At no time will both the right atrium and right ventricle be full, it’s just an ongoing ebb and flow of the atrium filling while the ventricle empties and vice versa.

As the blood from the right ventricle presses against a valve, it pushes the blood into the pulmonary artery.  The pulmonary artery has two off shoots, one leads to the right lung chamber, the other to the left chamber of the lung.  The blood passes from the artery and into one of the two lung chambers and becomes oxygenated from the oxygen within the lungs (University of Colorado).

When we inhale air, “about three tenths of a liter of oxygen is transferred from the alveoli to the blood (per) minute” (Merck & Co., Inc.).  The lungs receive about the same amount of carbon dioxide gas from the deoxygenized blood cells, which is what we exhale from the body.

The blood then leaves the lungs through the pulmonary vein to re-enter the heart, this time on the oxygenated side of the heart, into the left atrium.  The left atrium takes in all of the blood filling itself, much like the deoxygenated side atrium process, and then, again like the deoxygenated side, it contracts and empties into the chamber below it.  That chamber is the left ventricle and once it has filled, it empties into the aorta.  The aorta is a large blood vessel at the top of the heart and it distributes the now oxygenated blood throughout the entire body (Cardiovascular Consultants).

Work Cited

“Heart Anatomy.” Cardiovascular Consultants, LLP, 2006. Web. 17 Mar. 2010. <;.

Fremgen, Bonnie F., and Suzanne S. Frucht. “Cardiovascular System.” Medical Terminology. 4th ed. Prentice Hall, 2009. 134-36. Print.

Lujan, Barbara F., and Ronald J. White. Human Physiology in SpaceNational Space Biomedical Research Institute. College of Education , Texas A&M University. Weds. 17 Mar. 2010. <;.

“Exchanging Oxygen and Carbon Dioxide.” The Merck Manuals, Online Medical Library. Merck & Co., Inc., 2009. Web. 17 Mar. 2010. <;.

“The Circulatory System Part II: The Heart and Circulation of Blood.” Latent Semantic Analysis Texts. University of Colorado at Boulder, 31 Dec. 2006. Web. 17 Mar. 2010. <;.




One response

21 05 2010

Elementary my dear watson

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