What does the prefix epi- indicate in medical terminology?

What does the prefix epi- indicate in medical terminology?

• A. Within
• B. Upon or above
• C. Outside
• D. Behind

Answer: (B)

The idea behind this prefix is surface position: epi- means on or above a surface. It’s used when a structure sits on top of another or forms a outer surface. That’s why terms like epidermis, epicardium, and epithelium convey the sense of a layer on the surface—the outer skin, the outer layer of the heart, and the lining covering a surface, respectively. Other directional prefixes describe different positions (inside, outside, behind), so they don’t fit epi-.

The idea behind this prefix is surface position: epi- means on or above a surface. It’s used when a structure sits on top of another or forms a outer surface. That’s why terms like epidermis, epicardium, and epithelium convey the sense of a layer on the surface—the outer skin, the outer layer of the heart, and the lining covering a surface, respectively. Other directional prefixes describe different positions (inside, outside, behind), so they don’t fit epi-.