72 Questions
What is the primary requirement for initiating a physical or chemical process upon interaction with sunlight?
Absorption of light by an atom or molecule
Which region shows strong absorption of chromophores in human skin?
UVB, UVA, and blue visible region
Which of the following is an example of a chromophore with strong absorption in human skin?
Bilirubin
What can human skin be described as, in terms of its abundance of chromophores?
An abundant source of numerous chromophores
What is a major consequence of skin irradiation with ultraviolet radiation (UVR)?
Local and systemic immunosuppression
How does UVR lead to DNA damage?
Directly and indirectly through oxidative stress
What is the primary effect of increased Reactive Oxygen Species (ROS) production due to UVR exposure?
Local inflammation and connective tissue degradation
Which part of the skin undergoes major changes due to UVR exposure?
Dermis and the dermalepidermal junction
What is a major consequence of prolonged sun exposure on the skin?
Increased production of Reactive Oxygen Species (ROS)
Why is appropriate skin care recommended even after a sunbath without visible signs of erythema?
To counteract the effects of increased ROS production
How does ultraviolet radiation (UVR) lead to DNA damage?
By causing oxidative stress
Which part of the skin undergoes major changes due to exposure to ultraviolet radiation (UVR)?
Dermis
What are the most common forms of after-sun formulations?
Lotions, creams, and sprays
Which of the following is NOT an example of an active ingredient usually found in after-sun formulations?
Salicylic acid
What are some common compounds found in after-sun formulations?
Collagen, silk amino acids, unsaturated fatty acids
What is a typical source of active ingredients in after-sun formulations?
Root of liquorice
What is the primary purpose of using effective moisturizers in after sun preparations?
To reduce the signs and symptoms of dry, scaly skin
Which part of the skin undergoes major changes due to exposure to ultraviolet radiation (UVR)?
Epidermis
What is a major consequence of prolonged sun exposure on the skin?
Premature aging and wrinkling
How does ultraviolet radiation (UVR) lead to DNA damage?
By inducing ROS production
What is the primary purpose of incorporating anti-inflammatory substances into after-sun formulations?
To relieve erythema and its symptoms of pain, redness, and burning
What are some common compounds found in after-sun formulations?
Aloe vera, vitamin E, and menthol
Why is appropriate skin care recommended even after a sunbath without visible signs of erythema?
To prevent long-term skin damage caused by sun exposure
What is a major consequence of skin irradiation with ultraviolet radiation (UVR)?
Increased production of Reactive Oxygen Species (ROS)
What property of Witch Hazel makes it effective for skin and recognized for its soothing properties?
High concentration of astringent tannins
What category has Witch Hazel been approved for as an OTC product?
Astringent and skin-protecting
What effect does Witch Hazel have on erythema (skin redness)?
Suppressing erythema
What contributes to the low toxicity profile of Witch Hazel?
Astringent and antioxidant properties
What is the primary benefit of aloe vera gel in after sun products?
Provides a cooling effect
What is the main effect of ultraviolet radiation (UVR) on the skin?
Leads to DNA damage
What is the primary reason for recommending appropriate skin care even after a sunbath without visible signs of erythema?
To maintain skin health
What is the major consequence of prolonged sun exposure on the skin?
Skin damage and visible signs of aging
Why are cooling agents like menthol and alcohol incorporated into after-sun products?
To soothe and alleviate the sensations of warmth and tenseness of sun-irritated skin
What is the primary benefit of incorporating camphor into after-sun products?
To soothe and alleviate sun-irritated skin
What is the purpose of using cooling agents in after-sun formulations?
To soothe and alleviate the sensations of warmth and tenseness of sun-irritated skin
What effect do cooling agents in after-sun products have on sun-irritated skin?
Soothe and alleviate sensations of warmth and tenseness
What is the primary purpose of using antioxidants in after-sun preparations?
To replenish the depleted antioxidant pool and reinforce antioxidant defenses
Which of the following substances is NOT mentioned as an example of an antioxidant used in after-sun preparations?
Menthol
What is the main focus of incorporating vitamins A, C, and E series into after-sun preparations?
To boost or reinforce antioxidant defenses of the skin
What is the purpose of using plant polyphenols from green tea in after-sun preparations?
To boost or reinforce the antioxidant defenses of the skin
What type of antioxidants are found in the human skin?
Lipophilic and hydrophilic
Which skin layer would benefit the most from increased antioxidant capacity?
Stratum corneum
Which of the following is a hydrophilic antioxidant found in the human skin?
Vitamin C
What type of antioxidants are ubiquinones and carotenoids categorized as in the human skin?
Lipophilic
What is the main role of green tea extract when applied topically for UV protection?
To induce DNA repair
Which chemical constituent of green tea is specifically mentioned to reduce UV-carcinogenesis in animal models?
Epigalocatechin gallate (EGCG)
What is the primary function of green tea polyphenols in relation to UV protection?
Mediation of UV-protective effects via induction of DNA repair
Which chemical constituent of green tea is NOT mentioned in the text?
Theanine
What is the primary benefit of shea butter in skin care products?
Protection against UV radiation
Which compound found in shea butter is responsible for activating cellular growth stimulation?
Phytosterols
What is the main effect of shea butter on skin regeneration?
Cellular growth stimulation
What is the role of shea butter's antioxidant butylated hydroxytoluene in skin care?
Protection against UV radiation
What is the effect of painting extra virgin olive oil (EVOO) on the skin immediately after UVB radiation?
It reduces the number of skin cancers and ROS-induced DNA damage
Which component of olive oil has been found to reduce ROS-induced skin damage?
Oleuropein
What has generated a renewed interest in artificial tanning products?
Increased awareness of the hazards of UV light exposure
What are the better formulations of sunless or self-tanners with improved aesthetics more widely available for?
Achieving a tanned appearance
What is the primary role of dihydroxyacetone (DHA) in sunless or self-tanners?
Enhancing skin pigmentation by staining
What is the site of action for dihydroxyacetone (DHA) in the skin?
Stratum corneum
What happens to dihydroxyacetone (DHA) when heated to effect a solution in alcohol, ether, or acetone?
It reverts to the monomeric form
What is the classification of dihydroxyacetone (DHA) in the International Cosmetic Ingredient Dictionary and Handbook?
Colorant or colorless dye
What is the usual concentration range of DHA in self-tanning products?
2.5% to 10%
What is the function of formulating with silicones in self-tanning products?
Obtaining the spreadability of oils
How does minimizing the particle size of the micelles in the emulsion improve the formulation of self-tanning products?
Improves uniformity of spreading
In which type of emulsion is DHA predominantly formulated for self-tanning products?
O/w emulsions
What type of products are more readily accepted by consumers than creams, due to ease of spreadability and aesthetics?
Gels
Which type of skin would be more suitable for products formulated in gel or alcoholic vehicles?
Oily skin
Which type of products may produce a more intense tan due to greater applied film thickness?
Creams
What type of skin care products would be most suitable for dry-skin types by the addition of emollients and humectants?
After-sun lotions
What is the primary effect of dihydroxyacetone (DHA) on SPF in sunless or self-tanners?
It provides only SPF 3 or 4
What is the classification of dihydroxyacetone (DHA) in the International Cosmetic Ingredient Dictionary and Handbook?
Colorant
What contributes to the low toxicity profile of Witch Hazel?
High tannin content
How does ultraviolet radiation (UVR) lead to DNA damage in the skin?
By creating reactive oxygen species
Learn about the interaction of sunlight with human skin, including the processes of reflection, scattering, and absorption. Understand the role of chromophores in absorbing sunlight, particularly in the UVB, UVA, and blue visible region.
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