Emergency Medical Technician (EMT) Intermediate Practice Exam

During Stage 1 hemorrhage, how does the body primarily compensate?

1. Vasodilation of blood vessels

2. Constriction of the vascular bed

3. Increased heart rate

4. Fluid retention by kidneys

The correct answer is: Constriction of the vascular bed

During Stage 1 hemorrhage, the body primarily compensates through constriction of the vascular bed. This response is critical for maintaining blood pressure and ensuring that vital organs continue to receive an adequate blood supply despite the loss of blood volume. When blood volume decreases due to hemorrhage, the body initiates a series of physiological responses to counteract the effects of this fluid loss. Constriction of blood vessels, known as vasoconstriction, helps to reduce the diameter of blood vessels, which increases vascular resistance and helps to sustain blood pressure levels. This mechanism is a part of the body's immediate response to hemorrhage and is regulated by the autonomic nervous system, particularly the sympathetic system, which is activated during times of stress or injury. Other potential compensatory responses during hemorrhage, such as increased heart rate or fluid retention by the kidneys, may occur later as the body continues to try to restore normal function. However, the primary and immediate response during Stage 1 is the constriction of blood vessels to maintain perfusion to essential organs and systems.