Epinephrine stimulates the ________ response, increasing blood pressure and relieving bronchospasm.

• A. Parasympathetic
• B. Sympathetic
• C. Cardiac
• D. Respiratory

Answer: (B)

Epinephrine triggers the fight-or-flight response by activating the sympathetic nervous system. It acts on adrenergic receptors throughout the body to produce coordinated sympathetic effects: alpha-1 receptors on blood vessels raise vascular tone and blood pressure, beta-1 receptors in the heart increase rate and force of contraction (also contributing to higher pressure), and beta-2 receptors in the lungs cause bronchodilation, relieving bronchospasm. This combination explains both the rise in blood pressure and the relief of bronchospasm described in the question. The parasympathetic system would produce opposite effects on these tissues, and labeling this as a cardiac- or respiratory-focused response would miss the broader sympathetic activation at work.