A 64-year-old man is brought into the emergency room after experiencing more than 3 h of increasing chest pain that was unrelieved by rest, antacids, or nitroglycerin. He complains of nausea without vomiting. Further questioning reveals a two-year history of exertional angina pectoris (pressing chest pain that often radiated along the inner aspect of the left arm when the patient climbed one flight of stairs). Propranolol, which reduces the response of the heart to stress, and nitroglycerin, which dilates systemic veins as well as coronary arteries, had been prescribed previously. On physical examination he is found to be acyanotic (normal blood oxygenation), tachypneic (rapid breathing), tachycardiac (rapid pulse rate) with a regular rhythm, and diaphoretic (sweating).This patient's tachycardia probably is mediated by reflex arcs associated with decreased cardiac output and possibly reduced blood pressure. The visceral efferent (motor) pathway of this cardiac response is mediated by which of the following?
A. Carotid branches of the glossopharyngeal nerves
B. Greater splanchnic nerves
C. Phrenic nerves
D. Sympathetic cervical and thoracic cardiac fibers
E. Vagus and recurrent laryngeal nerves
A. Carotid branches of the glossopharyngeal nerves
B. Greater splanchnic nerves
C. Phrenic nerves
D. Sympathetic cervical and thoracic cardiac fibers
E. Vagus and recurrent laryngeal nerves
