Physiology: Blood Circulation in the Body

The human body performs many functions and processes to ensure the proper functioning of all organs. The most crucial process is blood circulation. The blood circulating in the body is either full of oxygen or without oxygen. The circulation system is cyclic, with the lungs, heart, and kidneys forming the basic parts of the system (Nazario, 2020). The interaction between these three parts makes it possible for the body to get enough blood into the organs. The essay describes normal blood flow from the kidneys to the heart, through the heart, and back to the kidney.

Blood flow to and from the kidney

The kidney receives blood through the renal artery from the main aorta. The human body has a right renal artery and a left one. The left one takes blood to the left kidney, while the right takes blood to the right kidney (Nazario, 2020). Renal arteries branch to small veins and capillaries until the blood approaches the nephrons. The blood entering the kidneys has been wasted, and thus, after entering the nephrons, tiny blood vessels filter the wastes in the blood. The blood leaves the kidney using the renal veins to the heart. Therefore, renal veins drain impure blood from the kidneys while the arteries provide oxygenated blood to the aorta.

What happens in the heart?

The mammalian heart is the organ for pumping blood to different body organs. Its pumping organism is so efficient and unidirectional as it has valves preventing the backflow of blood. The heart has four chambers, two on both sides, both left and right. Each side has one atrium at the top and one ventricle at the bottom. Every chamber has a main vessel performing specific tasks (Levitzky, 2018, p. 47). The two atria receive blood while the ventricles pump blood out of the body. Blood from the kidney enters the right atrium and flows down to the right ventricle through the valve. The right ventricle then expands, pumping the deoxygenated blood to the lungs.

What happens in the lungs?

The lungs are fundamental in blood circulation as blood oxygenation happens in the air sacs. When the deoxygenated blood leaves the heart, it flows toward the lungs through the pulmonary artery. The blood moves to tiny blood vessels in the pulmonary artery. Oxygen flows into the blood through the vessel walls from the air sacs. At the same time, carbon dioxide passes from the blood to the air sacs. Therefore, the blood becomes oxygenated again (Levitzky, 2018, p. 45). The blood moves through the pulmonary vein to the left atrium and drops into the left ventricle through the valve. The chamber contracts after the blood enter the left ventricle, closing the valve between the atrium and the ventricle. After the valve closes, the left ventricle contracts, forcing the blood out through the aorta to significant organs in the body, and the kidney, which purifies the blood. After the blood enters the kidneys, the cycle repeats itself.

Blood circulation involves three main organs: the heart, lungs, and kidneys. Blood oxygenation happens in the lungs; oxygen is added to the blood. Later, the blood moves to the heart, the pumping organism. The blood is pumped to other organs and the kidney to remove any waste. The essay describes blood flow from the lungs to the kidney through the heart.


Levitzky, M. G. (2018). Chapter 7. Transport of oxygen and carbon dioxide in the blood. In Pulmonary Physiology (8th ed.). McGraw Hill.

Nazario, B. (2020). How the heart works. WebMD.

Removal Request
This essay on Physiology: Blood Circulation in the Body was written by a student just like you. You can use it for research or as a reference for your own work. Keep in mind, though, that a proper citation is necessary.
Request for Removal

You can submit a removal request if you own the copyright to this content and don't want it to be available on our website anymore.

Send a Removal Request