Question

What is the source of urea in the body?

Answer 1

Hint: Urea is an organic compound with the chemical formula, CO$(${NH}_{2}$)_{2}$. Urea is also known as carbamide. Urea is the main nitrogen-containing compound in mammals.

Complete answer:
Urea plays an important role in the metabolism of compounds containing nitrogen.
Urea is highly soluble in water and it is a colourless and odourless solid. Urea is a non-toxic compound. Urea is neither acidic or basic when dissolved in water.
Urea is majorly used by the body in the excretion of nitrogen. Urea is formed in the liver by the combination of two ammonia molecules with one carbon dioxide molecule. This happens through the urea cycle. Urea is a source of nitrogen and is widely used in fertilizers. Urea is an important raw material for the chemical industry.
The synthesis of urea occurs through the urea cycle. It occurs either due to the oxidation of amino acids or ammonia. Urea also plays a major role in the reabsorption of water and mineral ions from the excreted urine. The reabsorption of water and minerals occurs because of the countercurrent exchange system of the nephrons of the kidneys.

Note:
The absorption of urea in the inner medullary collecting ducts of the nephrons increases the osmolarity of the medullary fluid surrounding the thin descending loop of Henle. This increase in osmolarity facilitates the reabsorption of water.
The reabsorbed urea flows back into the thin descending loop of Henle with the help of the urea transporter 2. The urea then flows through the collecting ducts into the excreted urine.