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Photobiomodulation Science Flashcards

7 cards from real CLT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Photobiomodulation Science flashcards as text

  1. Which reactive oxygen species (ROS) produced during PBM acts as a secondary messenger at low levels?

    Answer: Superoxide and hydrogen peroxide

    Low-level superoxide and hydrogen peroxide generated during PBM act as secondary messengers that activate transcription factors like NF-κB.

  2. The process by which PBM activates gene expression through transcription factors is called:

    Answer: Photomodulation of signal transduction

    PBM stimulates signaling cascades that activate transcription factors (NF-κB, AP-1, HIF-1α), leading to altered gene expression and cellular responses.

  3. At which approximate tissue depth does 810 nm near-infrared light lose approximately 50% of its intensity?

    Answer: 1–5 mm

    Near-infrared light at 810 nm typically loses about half its intensity within the first few millimeters of tissue, though deeper structures still receive therapeutic doses.

  4. Which mechanism explains PBM's ability to reduce inflammation through mast cell modulation?

    Answer: PBM stabilizes mast cell membranes, reducing degranulation and histamine release

    PBM can photobiomodulate mast cells by stabilizing their membranes, decreasing degranulation and the subsequent release of pro-inflammatory histamine.

  5. What is the primary difference between Class 3B and Class 4 therapeutic lasers in PBM?

    Answer: Class 4 lasers have power output above 500 mW and pose greater thermal risks

    Class 4 lasers exceed 500 mW output, enabling faster treatment and deeper penetration but also carrying greater risk of thermal injury compared to Class 3B.

  6. Which physiological effect of PBM on microcirculation contributes to tissue healing?

    Answer: Vasodilation via NO release, increasing perfusion and oxygen delivery

    PBM-induced NO release causes local vasodilation, improving microcirculation and delivering more oxygen and nutrients to healing tissue.

  7. Which of the following best describes the concept of 'fluence rate' in PBM dosimetry?

    Answer: Power per unit area (irradiance) measured in W/cm²

    Fluence rate (irradiance) is the power delivered per unit area (W/cm²) and determines how quickly energy is deposited in tissue during PBM treatment.