Certified Paraoptometric (CPO) Practice Exam 2026

The term that describes the state of tension or pressure in a bodily system is "Ton." In medical terminology, "ton" is often used in contexts such as "tonicity," which refers to the degree of tension or pressure within muscles and other tissue. This concept is essential in understanding how muscles contract and relax, as well as how various systems in the body maintain homeostasis—balancing pressures and tensions to function effectively. Thus, "Ton" effectively captures the idea of internal pressure and tension in bodily systems, making it the correct choice. The other terms listed do not convey this specific physiological meaning.