Anatomy & Physiology for Laser Therapy Flashcards

Which anatomical eye structure is most at risk for thermal injury during laser treatments performed near the periorbital area?

Answer: Retina

The retina, which contains melanin and is richly vascularized, can concentrate laser energy to damaging levels, making retinal injury the most serious ocular risk.

The Bowen's layer (stratum granulosum) is involved in laser therapy considerations because it:

Answer: Is where keratohyalin granules form, establishing the water barrier of skin

The stratum granulosum contains keratohyalin granules that initiate keratin cross-linking, forming the lipid-protein barrier that affects how laser energy is distributed through the epidermis.

In photobiomodulation, what is the term for the dose-response phenomenon where both very low and very high doses are less effective than an intermediate optimal dose?

Answer: Biphasic dose response (Arndt-Schulz law)

The biphasic dose response (Arndt-Schulz law) describes how low-level laser therapy has an optimal energy range, with both insufficient and excessive doses producing diminished biological effects.

Which anatomical feature of sebaceous glands makes them relevant to laser treatment of acne?

Answer: They open into hair follicles and can harbor P. acnes bacteria targeted by blue light lasers

Sebaceous glands empty into hair follicles where P. acnes bacteria produce porphyrins that absorb blue light, making the folliculosebaceous unit the target in photodynamic acne treatment.

What is the primary physiological reason that low-level laser therapy can reduce edema after musculoskeletal injury?

Answer: It stimulates lymphatic vessel contractility and enhances lymphatic drainage

Low-level laser therapy enhances lymphatic smooth muscle contractility and photobiomodulation of lymphangions, improving drainage of interstitial fluid and reducing edema.

Which type of collagen predominates in scar tissue and is different from normal dermal collagen, a distinction important in laser scar remodeling?

Answer: Type III collagen in random orientation replacing normal basket-weave Type I

Scar tissue contains Type III collagen laid down in parallel bundles rather than the normal basket-weave pattern of Type I collagen, and fractional laser therapy promotes remodeling toward normal architecture.

The dermal-epidermal junction (basement membrane zone) is clinically relevant in ablative laser resurfacing because damage here can lead to:

Answer: Permanent loss of the epidermal barrier and scarring risk

The basement membrane zone anchors the epidermis to the dermis, and its disruption during ablative laser resurfacing increases the risk of scarring and impaired wound healing.