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CHAPTER 11 PROPERTIES OF THE HAIR AND SCALP 2012 Edition. Q. What are the two ADD: chief purposes of hair?. Protection Adornment. Add to the side bar: Hair is an appendage of the skin. http://beautyeditor.ca/2009/10/27/save-vs-splurge-argan-oil-hair-treatments/. TRIC OLOGY.
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CHAPTER 11 PROPERTIES OF THE HAIR AND SCALP 2012 Edition
Q. What are the two ADD: chief purposes of hair? • Protection • Adornment Add to the side bar: Hair is an appendage of the skin http://beautyeditor.ca/2009/10/27/save-vs-splurge-argan-oil-hair-treatments/
TRICOLOGY • scientific study of hair, its diseases, and care • comes from Greek words: Trichos=hair ology=the study of
Integumentary System ~the outer covering that encloses the entire body • includes the hair, skin, nails, and glands ***is the largest and fastest growing organ body http://images.google.com/imgres?q=cross+section+of+skin+diagram&hl=en&gbv=2&biw=1008&bih=588&tbm=isch&tbnid=1HN3S_H2yA6bwM:&imgrefurl=http://www.elcosh.org/en/document/322/d000303/contact-derm-toolbox-talk.html&docid=0S3J3vPqFij8MM&imgurl=http://www.elcosh.org/record/document/322/image3.jpg&w=280&h=323&ei=75yuTsGlBYbn0QGeheXHDw&zoom=1&iact=rc&dur=534&sig=115570578519706265263&page=2&tbnh=105&tbnw=91&start=15&ndsp=17&ved=1t:429,r:2,s:15&tx=49&ty=84
hair is divided into two parts: Hair root ~located below the surface of the epidermis (outer layer of the skin) Hair shaft ~projectsabovethe epidermis
Structures of the Hair Root The main structures are: • Follicle • Bulb • Dermal papilla • Arrector pili muscle • Sebaceous glands
Follicle ~ tube-like depression or pocket in the skin or scalp ~ contains the hair root ~ distributed all over the body ~ except *palms of the hands *soles of the feet ~ multiple hairs/one follicle
The follicle “Tunnel” epidermis(outer layer of the skin) dermis (inner layer of the skin) Surrounds the dermal papilla Internet source: acne-site.com
Hair bulb-the lowest area or part of the hair strand. • thickened, club-shaped part of the hair root • fits over and covers thedermal papilla Internet source: Missinglink.ucsf.edu
Dermal papilla ~ cone-shaped elevation ~ base of the hair follicle ~ fits into hair bulb. • contains theblood and nervesupply • providesnutrients • “mother of the hair”
Arrector pili: • small, involuntary muscle ~ base of the hair follicle. • Strong emotions(fear) • or cold ~ contracts “goose bumps” www.unexpectedpages.com/.../goosebumps.jpg
Sebaceous glands ~ oil glands ~ connected to the hair follicles. ~ secretes oily substance ~ sebum ~ lubricates
Structures of the Hair Shaft Three main layers • 1. Cuticle ~ outermost layer of hair ~ overlapping layer of transparent, scale-like cells ~ shingles on a roof
~provides a barrier/protects inner structure ~lies tightly against the cortex ~ creates shine, smooth silky feel **Show----Feel hair strand (both ways) • hair’s primary defense against damage Internet source: the gentle touch.com
Individual cuticle scales are attached to the cortex ***The hair has only one cuticle layer Q. Why are we cautioned that there is only one cuticle layer?
Swelling the hair: ~ raises the cuticle layer ~ opens the space between the scales ~allows liquids to penetrate
Internet source: Hairdressersus.com Damaged cuticle • Haircolor, permanent waving solutions, and chemical hair relaxers must have an alkaline (base) pH to penetrate the cuticle layer • Swells cuticle/lifts/exposes cortex • Q. Is haircolor spelled correctly?
Cortex-is the middle layer of the hair ~ fibrous protein ~elongated cells ~melanin pigment Q. What does the word melanin mean?
~ elasticity of the hair ~ natural color ~ located in the cortex • all changes (physical or chemical)take place within the cortex • Activity: With a partner list on paper (be specific) • Q. Determine what services create a physical change to the hair and which ones create a chemical change to the hair. • 2 people from each table write two answers on flip chart paper
Answer: Physical-wet setting (rollers, pin curls, finger waves), thermal styling (includes blow drying, curling iron, flat iron, hot rollers, press and curl) Chemical-permanent haircolor, hair lightening, permanent waving, chemical relaxing
In book- page222 Internet source: Hairdressersus.com Womensnet.com
Medulla-the inner most layer ~ composed of round cells *missing medulla ~ very fine hair ~ naturally blonde hair ~coarse hair contains a medulla
Internet source: Ecobyte.com.au Bfro.net
All beard hair contains a medulla • not involved in salon services Add to side bar: Barba-hair of the face Capilli-hair on the head Cilia-hair of the eyelashes Supercilia-hair of the eyebrows
THE CHEMICAL COMPOSITION OF HAIR • composed of protein in the hair follicle ADD: keratin • This is where the hair shaft begins • living cells form • journey upward through the hair follicle
process called keratinization. • As the cells mature ~ fill up with a fibrous protein ~keratin ~move upward Killerstrands.blogspot.com
~ lose their nucleus ~ die ~ emerges from the scalp, ~ cells are keratinized ~ no longer living ~ nonliving fiber of keratinized protein
~ 90% protein ~protein made up of long chains of amino acids Main elements: (chemical composition) Carbon Oxygen Hydrogen Nitrogen Sulfur http://images.google.com/imgres?q=cohn%27s+elements+of+the+periodic+table&hl=en&gbv=2&biw=1024&bih=596&tbm=isch&tbnid=dUwFPL6QxJELcM:&imgrefurl=http://biology.clc.uc.edu/courses/bio104/atom-h2o.htm&docid=ML-VeqpxKSgnnM&imgurl=http://biology.clc.uc.edu/graphics/bio104/periodic.jpg&w=400&h=298&ei=WayuToiFA8O1gweb_b3KDw&zoom=1&iact=rc&dur=287&sig=115570578519706265263&page=2&tbnh=106&tbnw=141&start=16&ndsp=18&ved=1t:429,r:10,s:16&tx=61&ty=70
Referred to as the COHNS elements • Also found in skin and nails • Add: chemical composition Top of page shows the % of each element.
Amino acids-long chains of protein • joined together like pop beads(candy necklace) The chemical bond that joins the amino acids to each other is called a peptide bond or end bond.
A long chain of amino acids linked by peptide bonds is called a polypeptide. • spiral shape of coiled protein is called a helix. • Activity: • Do helix project http://scienceray.com/biology/proteins/
THE SIDE BONDS OF THE CORTEX • made up of millions of polypeptide chains • Polypeptide chains are cross- linked by three different types of side bonds:
Responsible for: • Extreme strength • Elasticity • Essential to: • Wet sets • Thermal styling • Permanent waving • Chemical hair relaxing
Three types 0f Side Bonds: • Hydrogen bonds • Salt bonds • Disulfide bonds • Q. In the chart, what can be said about the three types of bonds? Backreaction.blogspot.com
Hydrogen bond • weak physical side bond • Easily broken by waterorheat • Accounts for 1/3 of hair’s strength
Wetting the hair: • Allows the hair to be stretched and wrapped around rollers/rods • Reforms when the hair dries http://images.google.com/imgres?q=roller+sets+on+natural+hair&hl=en&biw=1024&bih=619&gbv=2&tbm=isch&tbnid=J1FgFtlgpV86eM:&imgrefurl=http://afropeanqueen.blogspot.com/2011/03/roller-set-re-done-and-hair-length.html&docid=tTmufLTEb1XB1M&imgurl=http://4.bp.blogspot.com/-0a8SssYfC6c/TY-912zvlcI/AAAAAAAAAbM/HqHSoMDKDW8/s1600/DSCN0672.JPG&w=1200&h=1600&ei=T0T9TpeTHZPAgAfKrp2XAg&zoom=1&iact=hc&vpx=611&vpy=185&dur=868&hovh=259&hovw=194&tx=108&ty=139&sig=115570578519706265263&page=10&tbnh=126&tbnw=103&start=171&ndsp=20&ved=1t:429,r:4,s:171
Salt bond • weak physical side bond • Depend on pH • Easily broken by -strong alkaline or acidic solutions • Accounts for 1/3 of hair’s strength
Disulfide bond ~strong chemical side bond • accounts for 1/3 overall strength • Not broken by heat or water • Broken by: ~ permanent waves ~ chemical relaxers ~alters the shape of the hair
Thio permanent waves (base) ~ break the disulfide bonds ~ reformed by thio neutralizer (acid) • Hydroxide chemical hair relaxers ~ break disulfide bonds ~ bonds are broken permanently (becomes lanthionine bond) ~ can never be reformed
Go over Figure 11-7 and 11-8 Read: Table 11-2 top of page Read: Did you know-next page
Hair Pigment: ~ pigment located in the cortex Melanin ~ tiny grains of pigment ~ cortex
The two main types: • Eumelanin • brownand black 2.Pheomelanin red /ginger yellow/blonde ~result: natural hair color- ratio of both
Wave Pattern • Refers to the shape of the hair strand Described as: • straight • wavy • curly • extremelycurly
result of genetics General rule: Asians ~extremely straight hair Caucasians ~straight to wavy hair African Americans ~extremely curly hair
all wave patterns ~ in all races • vary from strand to strand ~ same person’s head • theories to explain the cause of natural curly hair
One theory-the shape of the cross-section (round, oval, flat), determines the amount of curl, however, the shape of the cross-section does not always relate to the amount of curl. • Another theory-the result of one side of the hair strand growing faster than the other side, tension with in the strand causes the long side to curl around the short side. (not proven)