Which prefix means 'through' (and sometimes 'between')?

Which prefix means 'through' (and sometimes 'between')?

• A. Inter
• B. Endo
• C. Dia
• D. Peri

Answer: (C)

Prefixes in medical terms tell how a structure relates to others. When something goes through or across, the prefix dia- is used. It signals that a path passes from one side to the other, literally moving through a structure. A familiar example is diameter—the distance measured across a circle, traveling through its center from one boundary point to the opposite one. This sense of passing through is why dia- is the best fit for “through” (and, in some contexts, the idea of crossing from one side to another). By contrast, inter- means between, endo- means within, and peri- means around, so they don’t match the meaning of through.

Prefixes in medical terms tell how a structure relates to others. When something goes through or across, the prefix dia- is used. It signals that a path passes from one side to the other, literally moving through a structure. A familiar example is diameter—the distance measured across a circle, traveling through its center from one boundary point to the opposite one. This sense of passing through is why dia- is the best fit for “through” (and, in some contexts, the idea of crossing from one side to another). By contrast, inter- means between, endo- means within, and peri- means around, so they don’t match the meaning of through.