Certified Transport Registered Nurse Certification Practice Exam

Which of the following is a physiological effect of hyperthermia?

1. Vasoconstriction

2. Increased oxygen transport

3. Increased cardiac output

4. Improved renal function

The correct answer is: Vasoconstriction

The physiological effect of hyperthermia that is most commonly recognized involves increased cardiac output. When the body experiences hyperthermia, or an elevated body temperature beyond the normal range, the cardiovascular system responds to maintain homeostasis. As body temperature rises, the heart rate increases, leading to a higher cardiac output. This response is crucial for dissipating heat and ensuring that blood continues to circulate effectively throughout the body. The increased cardiac output helps facilitate enhanced blood flow to the skin, allowing for heat loss through radiation and evaporation, which is vital in regulating body temperature. In contrast, vasoconstriction typically occurs during hypothermia or in response to cold temperatures rather than heat. This process is designed to conserve body heat by reducing blood flow to the periphery. Therefore, during hyperthermic conditions, the body actually experiences vasodilation instead, which further aids in heat dissipation. Increased oxygen transport is also a consequence associated with the increase in cardiac output, rather than a direct physiological effect of hyperthermia itself. Improved renal function is not a physiological effect of hyperthermia either; in fact, hyperthermia can lead to renal impairment due to decreased blood flow and dehydration. Understanding these physiological responses aids in recognizing the importance of