Which prefix signifies "chest"?

The prefix "thoraco-" originates from the Greek word "thorax," which refers specifically to the chest area of the body. This term is commonly used in medical terminology to denote anything related to the thoracic cavity or chest, including structures such as the lungs, heart, and surrounding tissues.

For instance, the word "thoracotomy" refers to a surgical procedure involving an incision into the chest wall. This highlights how "thoraco-" is appropriately associated with the chest in various medical contexts, making it the correct choice for the prefix that signifies "chest."

In contrast, other prefixes like "hypo-" refer to conditions of deficiency or lower than normal, "veno-" pertains to veins, and "mammo-" relates to the breast, which situates them in different anatomical contexts and confirms why they do not represent the chest specifically.