AEMCA Practice Exam

What happens in neurogenic shock?

1. The body experiences high blood pressure

2. Loss of sympathetic tone occurs below the injury site

3. Vasoconstriction of blood vessels takes place

4. An increase in heart rate is noted

The correct answer is: Loss of sympathetic tone occurs below the injury site

In neurogenic shock, the key event is the loss of sympathetic tone occurring below the level of the spinal cord injury. This loss of sympathetic nervous system activity results in the inability to constrict blood vessels, leading to vasodilation. Consequently, the overall vascular resistance decreases, which can result in hypotension (low blood pressure). Unlike other forms of shock, such as hypovolemic or cardiogenic shock, where blood pressure may be elevated initially, neurogenic shock will typically present with low blood pressure and bradycardia (a decrease in heart rate). Understanding the physiological changes during neurogenic shock clarifies why the other options do not represent the condition accurately. For instance, high blood pressure and vasoconstriction are associated with a functioning sympathetic response, which is not the case in neurogenic shock. Similarly, an increase in heart rate would indicate a compensatory mechanism that is absent in this type of shock due to the unopposed parasympathetic activity that often accompanies the loss of sympathetic tone.