The combining form cyst(o) refers to which meaning?

• A. Circle
• B. Bladder, sac
• C. Down, from
• D. Tooth

Answer: (B)

The combining form cyst(o) denotes bladder or sac. It comes from a word root meaning a sac or the urinary bladder, and appears in terms like cystitis (inflammation of the bladder) and cystoscope (instrument to examine the bladder). It’s used to refer to a sac or bladder in medical terms, rather than circle or roundness, downward direction, or a tooth.