A direct outcome of applying diathermy and radiation is an increase in which physiologic parameter?

• A. Nerve conduction velocity
• B. Circulation
• C. Bone density
• D. Lymphatic drainage

Answer: (B)

Raising tissue temperature with diathermy and radiant energy causes local blood vessels to dilate, increasing blood flow to the treated area. That heightened perfusion is the direct physiologic change you’d expect, so the circulation goes up.

Nerve conduction velocity can be influenced by temperature, but the immediate, primary effect of these heat modalities is increased circulation; bone density isn’t acutely affected, and lymphatic drainage isn’t the direct parameter changing from a single heating session.