CLT Photobiomodulation Science 2

Question 1

Which cellular organelle is the primary chromophore target in photobiomodulation therapy?

Accepted Answer

Mitochondria

Answer

Mitochondria contain cytochrome c oxidase, the primary chromophore that absorbs red and near-infrared light during PBM therapy.

Question 2

The Arndt-Schulz Law as applied to photobiomodulation states that:

Accepted Answer

Weak stimuli excite, optimal stimuli promote, and excessive stimuli inhibit biological activity

Answer

The Arndt-Schulz Law describes the biphasic dose-response relationship where too little light has no effect and too much light can inhibit or damage tissue.

Question 3

Which of the following best describes the 'optical window' in PBM therapy?

Accepted Answer

600–1100 nm range where light penetrates tissue most effectively

Answer

The therapeutic optical window (600–1100 nm) minimizes absorption by water and hemoglobin, allowing deeper tissue penetration.

Question 4

Retrograde axonal transport of photobiomodulation signals primarily affects which system?

Accepted Answer

Nervous system

Answer

PBM light absorbed by peripheral nerve endings can trigger retrograde signals along axons to cell bodies, affecting neurological function.

Question 5

What is the role of nitric oxide (NO) in photobiomodulation mechanisms?

Accepted Answer

It is displaced from cytochrome c oxidase, restoring mitochondrial function

Answer

In hypoxic or stressed tissue, NO binds and inhibits cytochrome c oxidase; PBM light displaces this NO, restoring normal electron transport.

(CLT) Certified Laser Therapist Practice Test

(CLT) Certified Laser Therapist Practice Test

CLT Photobiomodulation Science 2