Which substances are removed from blood plasma by the kidneys?

The kidneys are essential organs in the body's urinary system responsible for filtering waste products and excess substances from the blood plasma. The substances removed by the kidneys include:

1. Urea: Urea is the main nitrogenous waste product of protein metabolism. It is produced when the liver breaks down amino acids.

2. Creatinine: Creatinine is a waste product that comes from muscle metabolism.

3. Uric Acid: Uric acid is the waste product of purine metabolism, purines being the building blocks of nucleic acids.

4. Excess Water: The kidneys regulate the body's fluid balance by removing excess water from the blood plasma.

5. Excess Electrolytes: Electrolytes such as sodium, potassium, chloride, and bicarbonate are regulated and maintained at optimal levels by the kidneys.

6. Toxins and Drugs: Various toxins, metabolic waste products, and certain drugs are removed from the bloodstream by the kidneys.

These substances, along with other waste products, are transported in the blood to the kidneys. Inside the kidneys, a complex process involving filtration, reabsorption, and secretion takes place, ensuring that essential substances are retained while waste products are eliminated in urine.