OBT Photobiomodulation Mechanisms & Cellular Effects 3

Question 1

Which of the following wavelength ranges is generally considered optimal for deeper tissue penetration in photobiomodulation?

Accepted Answer

780–1100 nm (near-infrared)

Answer

Near-infrared wavelengths (780–1100 nm) penetrate deeper into tissue because they experience less absorption by hemoglobin and melanin compared to shorter visible wavelengths.

Question 2

The term 'coherence' in laser light refers to:

Accepted Answer

Uniform phase relationship among photons, producing an ordered wavefront

Answer

Coherence describes the uniform phase relationship of laser photons, producing a highly ordered, collimated beam — a property that distinguishes laser from broadband LED light sources.

Question 3

During the inflammatory phase of wound healing, photobiomodulation primarily assists by:

Accepted Answer

Modulating macrophage polarization toward the M2 anti-inflammatory phenotype

Answer

Photobiomodulation promotes macrophage polarization from the pro-inflammatory M1 phenotype to the tissue-remodeling M2 phenotype, helping to resolve inflammation and initiate the proliferative phase.

Question 4

Which parameter determines how quickly photobiomodulation energy is delivered to tissue?

Accepted Answer

Irradiance or power density (mW/cm²)

Answer

Irradiance (power density), measured in mW/cm², describes the rate of energy delivery per unit area and directly affects how quickly the therapeutic dose accumulates in tissue.

Question 5

Photobiomodulation-induced upregulation of heat shock proteins (HSPs) in cells primarily contributes to:

Accepted Answer

Cellular protection, protein folding, and stress resistance

Answer

Heat shock proteins act as molecular chaperones that facilitate proper protein folding and protect cells under stress; their upregulation by photobiomodulation enhances cellular resilience and repair.

(OBT) Optical Beam Therapy Certification Practice Test

(OBT) Optical Beam Therapy Certification Practice Test

OBT Photobiomodulation Mechanisms & Cellular Effects 3