Cosmetology Practice: Hair, Scalp, Face, and Nail Services
Domain 1 tests the service knowledge behind every practical task: hair structure and analysis, scalp and skin assessment, nail structure, and the boundaries of each Florida license type. Expect scenario items - a client walks in with a specific history and you must choose the next correct action, not just name a technique.
Who may perform what
- A cosmetologist license covers hair, scalp, facial (skin care), and nail services.
- A facial specialist is limited to skin care and hair removal; no haircutting, chemical texturizing, or nails.
- A nail specialist is limited to manicuring, pedicuring, and nail extensions.
- A full specialist combines facial and nail services; hair braiders and hair wrappers hold narrow licenses for those techniques only.
Hair and scalp analysis
- Three layers: cuticle (overlapping scales, the barrier), cortex (about 90 percent of the fiber; holds melanin and the bonds that shape hair), medulla (core, sometimes absent).
- Side bonds: disulfide (strongest; broken by relaxers and permanent waves), hydrogen, and salt bonds (broken by water and pH change).
- Growth cycle: anagen (active, roughly 90 percent of scalp hair), catagen (transition), telogen (resting and shedding). Average growth is about 1.25 cm (half an inch) per month.
- Test before any chemical service: porosity (how readily the strand takes in and holds water), elasticity (a wet strand stretches and springs back), density (strands per square inch), and scalp condition.
- Scalp and skin sit near pH 4.5–5.5, which is why acid-balanced products respect the barrier.
Nail structure
- Nail plate, nail bed, matrix (manufactures the plate and determines thickness and curve), cuticle, eponychium, hyponychium, lunula, and free edge.
Worked example
A client with previously relaxed, color-treated hair wants six levels of lift in one appointment. Reasoning: relaxed hair has already had disulfide bonds broken; elasticity testing shows poor stretch and return, so overlapping high-lift lightener with sodium hydroxide is a predictable breakage. Correct action: decline the single-session service, strand test, lighten new growth only, tone the relaxed lengths, and book a follow-up. Document the consultation.
Traps that cost marks
- Confusing the matrix with the nail bed.
- Treating ringworm or pediculosis as a routine scalp condition instead of stopping the service and referring out.
- Assuming hair grows an inch a month, or that the hair shaft is living tissue.