Which combining form denotes joints?

• A. Cardi/o
• B. Coron/o
• C. Arthr/o
• D. Therm/o

Answer: (C)

Understanding combining forms helps you name body parts accurately. A combining form is a root plus a linking vowel used to form terms. For joints, the correct combining form is arthr/o, derived from the Greek word for joint. When you attach suffixes, you get terms like arthritis (inflammation of a joint), arthroplasty (surgical repair of a joint), and arthroscope (instrument to examine a joint). The other roots point to different structures or concepts: cardi/o refers to the heart, coron/o to the crown or coronary arteries, and therm/o to heat. Those do not denote joints, so they’re not correct here.