Question

Which blood vessel contains the lowest concentration of urea?

Answer 1

Urea is the excretory product that is excreted out of the body. Urea is excreted through the kidney in the urine. So, the blood vessel which drains the blood from the kidney will carry the lowest concentration of urea as the kidney has filtered out all the urea into the urine.

Complete answer:
To answer this question, we must know about the blood vessels entering and leaving the kidney and also the composition of the blood in the vessels. We all know that the kidney is the chief organ of excretion. It releases the body’s harmful waste and chemicals through urine. The urea is one of the major harmful substances which is produced in the liver through the process of amino acid breakdown. This urea is transported to the kidney by the help of the Renal artery which carries all the excretory substances from the body to the kidney where it is filtered out.

After the filtration and absorption, the hepatic veins carry the filtered blood from the kidney to the heart for oxygenation. The blood vessel that exits from the kidney that is the renal vein does not contain any toxic or harmful substances. It only contains glucose and other salts which are essential for our body.

So, Renal vein contains the lowest concentration of urea.

Note: All the veins carry deoxygenated blood from the organs to the heart for oxygenation except the pulmonary vein which carries oxygenated blood from the lungs to the heart. The renal vein joins the inferior vena cava. There is a renal vein for each kidney.