CLT Photobiomodulation Science 3

Question 1

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

Accepted Answer

Superoxide and hydrogen peroxide

Answer

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

Question 2

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

Accepted Answer

Photomodulation of signal transduction

Answer

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

Question 3

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

Accepted Answer

1–5 mm

Answer

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.

Question 4

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

Accepted Answer

PBM stabilizes mast cell membranes, reducing degranulation and histamine release

Answer

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

Question 5

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

Accepted Answer

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

Answer

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.

(CLT) Certified Laser Therapist Practice Test

(CLT) Certified Laser Therapist Practice Test

CLT Photobiomodulation Science 3