L12: Hair Cosmetics Flashcards
What are the general functions of hair?
- Natural function
- Social function
- Psychological function
What are the main structural components of the hair?
- Hair follicle
- Hair bulb
- Hair shaft
- Sebaceous gland
- Arrector pili muscle
What are the 3 layers of the hair shaft, starting from the outermost layer?
- Cuticle
- Cortex
- Medulla
What are the characteristics of the cuticle of the hair shaft?
- Overlapping scale-like structure made up of translucent, non-pigmented cells
- Composed of hard keratin protein
- Makes up 10 - 15% of the hair
What are the characteristics of the cortex of the hair shaft?
- Made up of densely packed spindle-shaped cells aligned along the long axis of the hair on the inner face of the cuticle
- Contains melanin granules that determine the hair colour
- Makes up 85 - 90% of the hair
What is the characteristic of the medulla of the hair shaft?
- Composed of honeycomb-like cells
Which layer of the hair shaft is not found in vellus hair and infant hair?
Medulla
Which layer of the hair shaft is responsible for brighter hair?
Medulla
Which layer of the hair shaft is responsible for the smoothness and softness of the hair?
Cortex
Which layer of the hair shaft confers protection and strength to the hair?
Cuticle
Why do we need to use conditioners for our hair?
To moderate static charges between hairs, as well as between hair and other materials for better manageability
How are charges formed on the hair?
- Rubbing
- Shampooing
What cause the hair to entangle easily?
Repulsive forces caused by electrical static charges formed on the hair
What may cause the strength of hair to decrease?
- Wet hair
- Deficiency in proteins
Are the number of hair follicles fixed at birth?
Yes
At which stage in life causes hair roots to thicken?
Puberty
What is responsible for the thickening of hair roots during puberty?
Androgens
What is the difference between terminal hair and vellus hair?
Terminal hair is thicker and darker, while vellus hair is less visible, finer and lighter in color.
Before puberty, terminal hair is limited to which body parts?
- Scalp
- Eyebrows
- Eyelashes
What are the 3 phases of the hair cycle?
- Anagen (Hair growth)
- Catagen (Growth stops)
- Telogen (Hair loss)
What are the two main hair growth patterns?
- Whorl
2. Cowlick