Which of the following best describes the mechanism of injury in neurogenic shock?

The mechanism of injury in neurogenic shock is primarily characterized by the relaxation of blood vessels, which leads to blood pooling. Neurogenic shock often occurs as a result of a spinal cord injury that disrupts the autonomic pathways responsible for vascular tone. When these pathways are disrupted, the sympathetic nervous system fails to maintain vascular constriction, causing the blood vessels to dilate. This dilation decreases systemic vascular resistance, leading to significant hypotension and inadequate blood flow to vital organs, ultimately resulting in shock.

The pooling of blood in the dilated vessels means that there is insufficient blood returning to the heart, further compounding the issue of inadequate perfusion. This is crucial for understanding neurogenic shock and differentiating it from other types of shock such as hypovolemic shock, where blood volume is critically low, and obstructive shock, which involves physical obstruction to blood flow.

In contrast, the other choices do not accurately depict the mechanism of injury in neurogenic shock. Blood vessel constriction, rupturing, or obstruction of air passages would involve different physiological processes and conditions that are not characteristic of neurogenic shock.