What percentage of normal body weight does circulating blood volume represent in adults?

Circulating blood volume constitutes about 7% of an adult's normal body weight, making it the correct choice. This percentage reflects the typical volume of blood in a healthy adult, which is approximately 5 to 6 liters depending on body size and composition. Understanding the relationship between body weight and blood volume is crucial in critical care, as it allows for better assessment of fluid status, shock assessment, and management of various medical conditions. Recognizing that blood volume is a constant percentage of body weight helps clinicians understand the physiological changes that can occur during fluid loss or gain, making this knowledge essential for providing effective patient care.