Which statement correctly pairs the shock type with its primary cause?

• A. Hypovolemic Shock — heart pump failure
• B. Cardiogenic Shock — blood or fluid loss
• C. Distributive Shock — vessel dilation causing low perfusion
• D. Obstructive Shock — physical blockage of circulation

Answer: (C)

The key idea is how the underlying mechanism of a shock type determines why tissue perfusion drops. In distributive shock, widespread vasodilation reduces systemic vascular resistance and enlarges the capacitance vessels, so blood pools away from the heart and the effective circulating volume falls. Even if total blood volume is not severely depleted, the distribution issue leads to low perfusion, making vessel dilation causing reduced tissue perfusion the best description.

The other statements don’t fit because hypovolemic shock is driven by loss of blood or fluids reducing preload and cardiac output, not heart pump failure. Cardiogenic shock stems from the heart’s inability to pump effectively, due to myocardial failure or severe dysfunction. Obstructive shock results from a physical blockage that impedes blood flow, such as a pulmonary embolism or pericardial tamponade.