What is the plural form of the word apex?

The plural form "apices" is derived from Latin, where many medical and scientific terms originate. In Latin, the correct plural for "apex," which means the tip or point of an object or structure, is "apices." This form is commonly used in anatomical terminology to describe the pointed ends of organs, such as the apex of the heart or lungs. The use of "apices" is widely accepted in both medical literature and practice, making it the correct choice for this question.

The other options either do not follow the standard pluralization rules or do not reflect the correct usage in medical terminology. For example, "apexa" and "apenges" do not align with established plural forms from Latin roots, while "apexes," although sometimes used, is less preferred within formal medical contexts.