APPLY THE PRINCIPLES OF HAIRDRESSING SCIENCE WRHHS301A

Hair Analysis - porosity Structure of skin Functions of skin 3 layers of hair Hair follicle shape 3 stages of hair growth Natural hair colour Hair Analysis - porosity - elasticity - density - texture Effects on hair - environmental - mechanical - chemical Chemistry pH Scale

Structure of skin

3 Layers of hair CUTICLE – protective layer outer layer cross section of hair CUTICLE – protective layer outer layer CORTEX – hair colour exists chemically effected MEDULLA – inner layer often not present in some hair types

Hair Follicle The angle of the follicle determines the shape of the hair Round=straight Oval=wavy Olliptical(flat)=curly

3 Stages of hair growth

Natural hair colour All natural hair colour contains a mixture of Black , brown, red & yellow colour pigments Black/brown pigments are called Eumelanin Red/yellow pigments are called Pheomelanin Hair colour results from the amount and % of one or both of these colour pigments

Hair Analysis Porosity Elasticity Density Texture

Effects on hair Environmental Chemical Mechanical

Chemistry Matter - everything, everywhere is matter - solids - liquids - gases Elements (118) - all matter is made up of elements Atoms - the smallest complete unit of an element - protons - neutrons - electrons Molecules - 2 or more atoms joined together by a chemical bond Chemical bond - amino acids - peptide bonds - side bonds ( salt / hydrogen / disulphide / Van Der Waal’s forces )

The pH Scale The pH scale is a unit of measurement that indicates whether a substance is acidic, neutral or alkaline

Project Picture of the Structure of skin Briefly describe each Functions of skin - inc: sweat gland / sebaceous gland 3 layers of hair and each function Hair follicle shape and the effect on hair 3 stages of hair growth, what occurs in each stage Natural hair colour, what is it? What makes up hair colour? Hair Analysis - porosity - elasticity - density - texture Effects on hair - environmental - mechanical - chemical Chemistry, briefly outline the chemistry behind hair pH Scale – hair & skin, shampoo, ammonia, peroxide, acid perm, alkaline perm, relaxer, neutraliser, bleach, tint, gel, hairspray