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Questions and Answers
What is the primary function of the cuticle in hair structure?
What is the primary function of the cuticle in hair structure?
Which component of hair is responsible for its color?
Which component of hair is responsible for its color?
What is the average diameter of intermediate filaments found in hair?
What is the average diameter of intermediate filaments found in hair?
How many overlaying cells form the cuticle layer?
How many overlaying cells form the cuticle layer?
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What is the primary composition of the cortex in hair?
What is the primary composition of the cortex in hair?
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What type of acids are found attached to the surface of the epicuticle?
What type of acids are found attached to the surface of the epicuticle?
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Which layer of the hair structure is highly swellable and has a low cysteine content?
Which layer of the hair structure is highly swellable and has a low cysteine content?
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What part of the hair is known as the visible part?
What part of the hair is known as the visible part?
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What type of cells make up the cortical cells of the hair cortex?
What type of cells make up the cortical cells of the hair cortex?
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Which structure surrounds the hair root and is connected to the sebaceous gland?
Which structure surrounds the hair root and is connected to the sebaceous gland?
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What is one of the 6 main categories of shampoo products?
What is one of the 6 main categories of shampoo products?
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How many main categories of shampoo products are mentioned?
How many main categories of shampoo products are mentioned?
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What role does the hair bulb have in hair growth?
What role does the hair bulb have in hair growth?
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What is the primary function of the Arrector pili muscle?
What is the primary function of the Arrector pili muscle?
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Which shampoo category is designed for frequent washing?
Which shampoo category is designed for frequent washing?
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What is the function of a clarifying shampoo?
What is the function of a clarifying shampoo?
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How thick is the hair shaft typically in an adult?
How thick is the hair shaft typically in an adult?
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What type of properties are associated with hair's interaction with external substances?
What type of properties are associated with hair's interaction with external substances?
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Which shampoo category combines cleansing and conditioning in one product?
Which shampoo category combines cleansing and conditioning in one product?
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What is the main purpose of hair's surface properties?
What is the main purpose of hair's surface properties?
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Which component of hair can detect movement through sensitive nerves?
Which component of hair can detect movement through sensitive nerves?
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What property does the Water Contact Angle (WCA) measure in hair fibers?
What property does the Water Contact Angle (WCA) measure in hair fibers?
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What technique is used to evaluate the luster and shine of hair fibers?
What technique is used to evaluate the luster and shine of hair fibers?
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Which of the following is NOT a mechanical property evaluated through the 3-Point Cantilever technique?
Which of the following is NOT a mechanical property evaluated through the 3-Point Cantilever technique?
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What does a Water Contact Angle (WCA) larger than or equal to 90° signify about a material?
What does a Water Contact Angle (WCA) larger than or equal to 90° signify about a material?
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The cuticle of hair provides which type of protection due to its structure?
The cuticle of hair provides which type of protection due to its structure?
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Which mechanical property describes a material's resistance to deformation under stress?
Which mechanical property describes a material's resistance to deformation under stress?
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What outcome is likely if frequent grooming reduces the intactness of the hydrophobic layer on hair?
What outcome is likely if frequent grooming reduces the intactness of the hydrophobic layer on hair?
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What is an outcome of using the torsional pendulum technique in evaluating materials?
What is an outcome of using the torsional pendulum technique in evaluating materials?
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What is the tensile strength range of hair fiber?
What is the tensile strength range of hair fiber?
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What influences the tensile properties of hair?
What influences the tensile properties of hair?
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How does the force generated by hair change when it is extended and held?
How does the force generated by hair change when it is extended and held?
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What is the primary reason for the decrease in force in extended hair fibers?
What is the primary reason for the decrease in force in extended hair fibers?
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In terms of sorption properties, how do Caucasian and Asian hair types compare?
In terms of sorption properties, how do Caucasian and Asian hair types compare?
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What occurs to hair volume when Caucasian hair is compared to Asian hair?
What occurs to hair volume when Caucasian hair is compared to Asian hair?
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Which of the following best describes the viscoelastic properties of human hair?
Which of the following best describes the viscoelastic properties of human hair?
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What is essential for the formation and maintenance of a hair style?
What is essential for the formation and maintenance of a hair style?
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What does the coefficient of friction in hair products primarily depend on?
What does the coefficient of friction in hair products primarily depend on?
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How does moisture and humidity affect hair behavior?
How does moisture and humidity affect hair behavior?
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What is the primary purpose of shampoo as a haircare product?
What is the primary purpose of shampoo as a haircare product?
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Which type of haircare product is specifically formulated for regular use and convenience?
Which type of haircare product is specifically formulated for regular use and convenience?
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What unintended effect can arise from friction due to grooming?
What unintended effect can arise from friction due to grooming?
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What is a common characteristic of dirt, including sebum, in relation to water?
What is a common characteristic of dirt, including sebum, in relation to water?
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What is the effect of electrostatic charges on hair styling?
What is the effect of electrostatic charges on hair styling?
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Which type of shampoo is intended to deeply cleanse hair and remove buildup from other products?
Which type of shampoo is intended to deeply cleanse hair and remove buildup from other products?
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Study Notes
Cosmetics Technology - Lecture 7 (Haircare Tech)
- Course: ELCT 1021
- Instructor: Dr. Shahir Aziz
- Lecture Focus: Haircare Technology
- Topics Covered: Hair Structure, Health, Physical Properties, Surface Properties
Hair Structure and Health
- Hair Fiber Structure: The visible part of the hair is the hair shaft (50-100 microns thick in adults). It consists of the cuticle (outermost layer), cortex (middle layer), and medulla (innermost layer). These layers contain microfibrils, pigments, and the Cell Membrane Complex (CMC).
- Hair Shaft Components: The innermost part is the medulla, the middle is the cortex, and the outer layer is the cuticle. The cortex is made of keratin protein fibers (65-95% weight).
- Hair Shaft Hierarchy: Keratin protein fibers make up the cortex, with melanin providing natural color and texture. The cuticle consists of 4-8 cell layers cemented by the Cell Membrane Complex (CMC), creating a protective membrane.
- Hair Root: Extending into deeper skin layers, the hair root is surrounded by the hair follicle (skin sheath), sebaceous gland, and arrector pili muscles. The bulb at the base of the hair root has the hair papilla providing blood/lymph (nutrients/growth) and nerve endings.
- Hair Growth: Hair papilla is the site of new cell generation, nourishment, and endocrine control.
Hair Fiber Physical Properties
- 1) Tensile Properties: Hair has high tensile strength (150-270 MPa). Strength varies with strain rate, humidity, and temperature (due to α-helix to β-sheet keratin transformation).
- 2) Stress Relaxation Properties: Hair is viscoelastic. If stretched rapidly and held the force decreases over time (due to peptide bond deformation).
- 3) Sorption & Swelling Properties: Both Caucasian and Asian hair have similar water sorption; however, Asian hair shows greater volume changes. The endocuticle and hair surface play a significant role.
- 4) Bending & Torsional Properties: Hair behavior under bending/twisting stresses is important in maintaining styles. Rigidity and mechanical properties like toughness, elastic modulus, flexibility, and plasticity are measured with torsional pendulum and 3-point cantilever techniques.
Hair Surface Properties
- 1) Wettability: The low surface energy of the cuticle (hydrophobic layer) prevents uniform water wetting. Washing and grooming can disrupt the cuticle's natural wettability profile.
- 2) Luster & Shine: Measured using a Goniophotometer which measures light reflected from the fiber surface, in terms of luminous flux, intensity distribution and source efficiency.
- 3) Friction & Electrostatic Charge Generation: Friction is related to grooming and product application. Frictional forces are dependent on cuticle cell orientation, lipo-protein content and resulting electrostatic charge, affecting flyaways. Humidity and moisture content also influence flyaways by increasing conductivity.
Haircare Products
- Shampoo: The primary haircare product for scalp cleansing, removing sebum, dandruff, environmental dust and other residues. Various types (regular, clarifying, daily-use, conditioning, 2-in-1, dry shampoo) cater to different hair types and needs.
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Description
Explore the fundamentals of Haircare Technology in this quiz based on Lecture 7 of ELCT 1021. Delve into the structure, health, and physical properties of hair, including its various layers and components. Understand how these aspects contribute to hair care and treatment.
