What is the combining form for 'skull'?

The combining form for 'skull' is accurately identified as "crani/o." This term derives from the Greek word "kranion," which refers specifically to the skull or cranium. In medical terminology, combining forms are used to create terms related to specific body parts or conditions.

For instance, "crani/o" is commonly seen in medical terms such as "craniotomy," which refers to a surgical procedure involving the opening of the skull, and "craniocerebral," which pertains to the skull and brain. The other options refer to different body parts: "cran/o" is not a recognized combining form for skull; "dors/o" pertains to the back area, and "femor/o" relates to the femur or thigh bone. Therefore, "crani/o" is the correct choice when referring to the skull in a medical context.