Nitrogenous Wastes: Types and Kidney Excretion

Nitrogenous wastes removed by the kidneys include:

- Urea: This is the main nitrogenous waste product of protein metabolism. Urea is produced in the liver and transported to the kidneys for excretion in the urine.

- Creatinine: Creatinine is a waste product of muscle metabolism. It is produced in the muscles and transported to the kidneys for excretion in the urine.

- Uric acid: Uric acid is a waste product of purine metabolism. Purines are found in some foods, such as meat, poultry, and fish, as well as in the body's own cells. Uric acid is excreted in the urine.

- Ammonia: Ammonia is a toxic waste product of protein metabolism. It is converted into urea in the liver and then excreted in the urine.

- Other nitrogen-containing compounds: The kidneys also excrete other nitrogen-containing compounds, such as amino acids, peptides, and proteins.