Certified Wildlife Rehabilitator Practice Test

Where does the filtration process predominantly occur in mammals?

1. Liver

2. Heart

3. Kidneys

4. Stomach

The correct answer is: Kidneys

The filtration process in mammals primarily occurs in the kidneys. These organs are essential for maintaining homeostasis by regulating body fluids, electrolytes, and waste products. The kidneys filter blood through specialized structures called nephrons, where filtration, reabsorption, and secretion of various substances take place. In the nephron, blood passes through a glomerulus, where small molecules, water, and waste are filtered out of the bloodstream and into the renal tubule. This process allows the kidneys to produce urine, which is then excreted from the body. By filtering the blood, the kidneys help to remove toxins, excess salts, and waste products, playing a crucial role in the body's overall health and function. Other organs mentioned, like the liver, heart, and stomach, have different functions. The liver is involved in detoxification and metabolism, the heart's primary role is to pump blood throughout the body, and the stomach aids in digestion rather than filtration. Hence, the kidneys clearly stand out as the main site for filtration processes in mammals.