Mr. Collins is a 60-year-old patient who was in a car accident earlier in the day. After an examination, the physician determines that Mr. Collins sustained no physical injuries, although the patient's blood pressure and heart rate are elevated. Mr. Collins reports that at the time of the accident he felt a high level of fear and he noticed that he had goose bumps and was sweating profusely. Currently, he reports feeling constipated. Explain the mechanics of Mr. Collins's physiological reaction to the stressful experience of an automobile accident and describe the division of the autonomic nervous system that is responsible for Mr. Collins's symptoms.
Though one can try to memorize which elements of the peripheral nervous system and associated neurotransmitters cause what effects, my approach to these kinds of scenarios is to develop a framework upon which to hang my hat. That framework may involve memorization parts, but only as a means to trigger a thought process allowing one to think through the objective and subjective findings. Mr. Collins demonstrates several findings over which he has no voluntary control; most of us who are not Tantric Yoga adepts cannot intellectualize our way to developing goose bumps, or cause ourselves to sweat. Those findings indicate that a non-voluntary, or autonomic, effect has occurred. Immediately, we can see that his reaction involves the autonomic nervous system which we know has two parts, e.g., the parasympathetic and the sympathetic divisions. So which one is involved in ...
Fear can provoke a classic fight or flight response involving activation of the sympathetic nervous system and physiologic preparation to meet a stressful event. Cardiovascular stimulation and gut smooth muscle inhibition are hallmarks of the response.