Final answer:
The patient's symptoms are caused by the stimulation of the sympathetic nervous system, not the parasympathetic nervous system.
Step-by-step explanation:
The patient's symptoms, such as increased heart rate, dilated pupils, and decreased blood pressure, are not caused by the stimulation of the parasympathetic nervous system. Instead, they are caused by the stimulation of the sympathetic nervous system. The sympathetic nervous system is responsible for the body's fight or flight response, which is activated during stressful or dangerous situations.
In this case, the severe injuries sustained in the motor vehicle accident are likely causing the body to release adrenaline and other stress hormones, which activate the sympathetic nervous system. This leads to an increased heart rate, dilated pupils, and decreased blood pressure, among other symptoms.
Therefore, the correct answer is not applicable, as the symptoms described are not caused by the stimulation of the parasympathetic nervous system.