Manitoba Nephrology Nurse Practice Test

What percentage of the body's total cardiac output is received by the kidneys?

1. 10%

2. 20%

3. 25%

4. 30%

The correct answer is: 25%

The correct answer is that the kidneys receive approximately 20-25% of the body's total cardiac output. This significant percentage is crucial for their function in filtering blood and regulating bodily fluids and electrolytes. The high proportion of cardiac output directed to the kidneys emphasizes their role in maintaining homeostasis and effectively responding to the body’s needs. The renal blood flow is necessary for glomerular filtration, which is the first step in urine formation, and this is essential for waste elimination and regulation of body fluids. Although it is commonly cited that about 20% is the norm, variations in cardiac output and physiological states can influence this figure. The kidneys' ability to filter a large volume of blood assists in regulating blood pressure, plasma osmolarity, and maintaining acid-base balance, which are critical components of overall health. Understanding this percentage is important for nephrology nurses as it relates to kidney function and systemic health.