QUESTIONS AND ANSWERS SURE A+
✔✔Trichology - ✔✔Study of hair, skin, and glands.
✔✔A mature hair strand is divided into two parts - ✔✔Hair Root and Hair Shaft
✔✔Hair Root - ✔✔Part of hair located below the surface of the epidermis.
✔✔Hair bulb - ✔✔lowest part of a hair strand. It is thickened, club-shaped that forms the
lower part of the hair root. Lower part of the hair bulb fits over and covers the derma
papilla.
✔✔Hair Shaft - ✔✔Portion of the hair that projects above the epidermis.
✔✔Hair Follicle - ✔✔Tube- like depression or pocket in the skin or scalp that contains
the hair root.
✔✔Cuticle - ✔✔Outermost layer of the hair. Single overlapping layer of transparent,
scale like cells that look like shingles on a roof.
✔✔Cortex - ✔✔Middle layer of the hair, protein core formed by elongated cells
containing melanin pigment. 90 percent of the total weight comes from this.
✔✔Medulla - ✔✔Innermost layer of hair composed of round cells. Common for very fine
and naturally blond hair to lack this. Not involved in salon services.
✔✔Keratinization - ✔✔Fiberous protein, cells that originate within the hair follicle.
✔✔COHNS - ✔✔Five elements found in hair and nails
✔✔Hair is 51% - ✔✔carbon
, ✔✔Hair is 21% - ✔✔oxygen
✔✔Hair is 6% - ✔✔hydrogen
✔✔Hair is 17% - ✔✔Nitrogen
✔✔Hair is 5% - ✔✔Sulfur
✔✔Amino Acids - ✔✔Units joined together end to end like pop beads.
✔✔Peptide Bond - ✔✔Known as end bond.
✔✔Long chain of amino acids linked by peptide bonds are called - ✔✔Polypeptide
chain
✔✔Proteins - ✔✔Long coiled complex polypeptide
✔✔Hydrogen Bond - ✔✔Physical, cross-linked bond that is easily broken by water or
heat.
✔✔Salt bond - ✔✔Weak, physical, cross linked bond between adjacent polypeptide
chains.
✔✔Disulfide Bond - ✔✔Strong chemical, side bond that is very different from the
physical bond of a hydrogen bond or salt bond.
Broken by thio perms, hydroxide relaxers, extreme heat.
✔✔Eumelanin - ✔✔Dark brown-black color to hair.
✔✔Pheomelanin - ✔✔Red and ginger color to hair to yellow and blond tones.
✔✔Wave Pattern - ✔✔Refers to hair shape and strand. Described as straight, wavy,
curly or extremely curly.
✔✔Straight Hair - ✔✔round cross section
✔✔Wavy or curly hair - ✔✔oval to flattened oval cross section
✔✔Extremely curly hair - ✔✔flattened cross section
✔✔Vellus Hair - ✔✔Known as *Lanugo* hair it is short, fine, unpigmented, and downy.