Which prefix means four, the extremities?

• A. Quadri-
• B. Tetra-
• C. Neo-
• D. Dys-

Answer: (D)

Four is conveyed in medical combining forms mainly by quadri- and tetra-. When discussing the extremities, quadri- is the form most often used in anatomy and clinical terms (for example, quadriceps are four muscles at the front of the thigh, quadriplegia is paralysis of four limbs). Tetra- also means four but is used more broadly in non-anatomical terms (tetra- in tetralogy, tetramer, etc.). Neo- means new, and dys- means bad or difficult, so they don’t indicate a quantity. So, for four extremities, quadri- is the best fit.