What is the plural form of the word atrium?

The plural form of the word "atrium" is "atria." This term derives from Latin, where many anatomical terms are based on their original forms. In Latin, "atrium" is a second declension noun, and its plural is formed by changing the "-um" ending to "-a," resulting in "atria." This usage is consistent in medical terminology, which often retains Latin forms to maintain clarity and precision in describing structures in the body.

A common practice in English, especially in scientific and medical contexts, is to use these Latin-derived plurals, as they reflect the historical roots of many medical terms. Thus, "atria" is the correct pluralization in this case, ensuring effective communication among professionals who rely on precise terminology.