What is indicated by the prefix "angi-" in medical terminology?

The prefix "angi-" in medical terminology is derived from the Greek word "angeion," which means "vessel." It specifically refers to blood vessels, including arteries and veins. Therefore, when you see "angi-" as part of a medical term, it indicates something related to blood vessels. For example, "angioplasty" refers to a procedure to restore blood flow through the artery. This understanding is crucial in medical contexts, where precision in terminology can significantly impact diagnosis and treatment.

The other options—cell, cancer, and head—do not relate to the meaning of the prefix "angi-." Hence, they are not applicable in this context.