In biologic media typical values for impedance range from _____ or ______.

In biologic media typical values for impedance range from _____ or ______.

• A. 1,250,000 to 1,750,000 rayls; 1.25 to 1.75 Mrayls
• B. 500,000 to 1,000,000 rayls
• C. 2,000,000 to 3,000,000 rayls
• D. 1,000 to 5,000 rayls

Answer: (A)

Biologic media have impedances in the mega-rayl range. Impedance is the opposition to current flow in a medium, and for tissues it reflects the combined effects of conductivity and permittivity of fluids and structures within the tissue. A representative, commonly cited range for tissues at typical measurement frequencies is about 1.25 to 1.75 million rayls, i.e., 1.25 to 1.75 megarayls. Expressing it as 1,250,000 to 1,750,000 rayls or as 1.25 to 1.75 Mrayls conveys the same value, just in different units. Other options fall well outside the typical tissue range or mix units in a way that doesn’t align with standard biological impedance values.

Biologic media have impedances in the mega-rayl range. Impedance is the opposition to current flow in a medium, and for tissues it reflects the combined effects of conductivity and permittivity of fluids and structures within the tissue. A representative, commonly cited range for tissues at typical measurement frequencies is about 1.25 to 1.75 million rayls, i.e., 1.25 to 1.75 megarayls. Expressing it as 1,250,000 to 1,750,000 rayls or as 1.25 to 1.75 Mrayls conveys the same value, just in different units. Other options fall well outside the typical tissue range or mix units in a way that doesn’t align with standard biological impedance values.