Which type of shock is most likely when a spinal cord injury prevents vasoconstriction?

• A. Septic
• B. Cardiogenic
• C. Neurogenic
• D. Anaphylactic

Answer: (C)

When the spinal cord is injured, the sympathetic nerves that normally keep blood vessels constricted can be disrupted. That loss of sympathetic vasoconstrictor tone allows unopposed parasympathetic activity, causing widespread vasodilation and pooling of blood in the venous system. The result is a drop in systemic vascular resistance and often hypotension, sometimes with bradycardia due to reduced sympathetic input to the heart. This pattern—vasodilation from loss of sympathetic tone after spinal injury—is characteristic of neurogenic shock, setting it apart from septic, cardiogenic, or anaphylactic shock, which arise from infection/toxins, pump failure, or allergic mediators, respectively.