What does the prefix "dromo" mean?

• A. Running
• B. Duct
• C. Pain
• D. Swelling

Answer: (A)

Dromo- comes from Greek and means running or a running course. In medical terms this idea of moving along a path shows up in how we describe the speed of electrical conduction, such as the heart’s conduction system. A dromotropic effect is about how fast impulses travel through that system—faster conduction is like faster running along the pathway. So the prefix is essentially about running. The other options point to different roots—duct relates to leading or carrying through a duct, pain is linked to prefixes like odyn- or alg-, and swelling to edema—so they don’t fit the meaning of dromo-.