Which type of shock occurs when the spinal cord is damaged and unable to control the tone of blood vessels?

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

Answer: (A)

Neurogenic shock arises when a spinal cord injury interrupts the sympathetic nerve pathways that keep blood vessels them normally constricted. Without this sympathetic tone, vessels dilate (vasodilation), blood pools in the venous system, and venous return to the heart drops, causing a fall in blood pressure. The loss of sympathetic input to the heart can also lead to a slower heart rate. This type of shock is distributive, centered on disrupted vascular tone rather than fluid loss or heart dysfunction. It differs from septic shock (infection-driven vasodilation and capillary leak), hypovolemic shock (loss of circulating blood or fluids), and anaphylactic shock (severe allergy with vasodilation and airway involvement).