Hair Growth Cycles, Characteristics, and Scalp Analysis

Vocabulary practice flashcards covering hair types, biological growth cycles, structural characteristics (texture, density, porosity, elasticity, growth patterns), and professional scalp analysis protocols.

Vellus Hair (Lanugo Hair)

Short, fine, unpigmented hair found on areas such as the forehead, eyelids, and bald scalp.

Terminal Hair

Longer, coarse, pigmented hair found on the scalp, legs, and arms that is more coarse than vellus hair.

Anagen Phase

The active growth phase that lasts $3-5\,\text{years}$ and determines hair length; approximately $90\%$ of hair is in this phase at any given time, growing at an average rate of about $\frac{1}{2}\,\text{inch per month}$.

Catagen Phase

The intermediate phase lasting about $10\,\text{days}$ where hair stops growing, deeper portions of the follicle begin to collapse, and the follicle shrinks and detaches from the dermal papilla.

Telogen Phase

The shedding and resting phase during which hair is released and falls out (about $50-150\,\text{hairs}$ daily), the follicle remains inactive for $3\,\text{months}$, and about $10-15\,\text{hairs}$ are present at any given time.

Hair Texture

The diameter of an individual hair strand (classified as coarse, medium, or fine), which can vary across different areas of the same head.

Coarse Hair

Hair with a larger diameter that tends to be stronger and more resistant to chemicals, responds differently to haircutting, and requires heavier styling aids that can overwhelm fine hair.

Fine Hair

Hair with a smaller diameter that is more delicate, easier to penetrate with chemicals, and easily weighed down or overwhelmed by heavy styling aids.

Hair Density

The number of individual hair strands per square inch on the scalp, indicating total hair quantity; described as thin, medium, thick, or low to high.

Growth Pattern

The direction in which hair emerges from the scalp, determined by the angle of the follicle, which directly affects how the hair is cut.

Cowlick

An abnormal hair growth pattern characterized by a tuft of hair that stands straight up.

Whorl

An abnormal hair growth pattern in which the hair grows in a circular pattern.

Hair Stream

An abnormal growth pattern in which follicles grow in the same sloped direction, causing hair to flow in a stream-like direction.

Wave Pattern

The amount of movement in the hair strand, classified as straight, wavy, curly, or extremely curly.

Hair Elasticity

The ability of the hair to stretch and return to its original length without breaking; an indicator of overall health, strength, and curl retention.

Low Elasticity

Hair that does not stretch and is dry and brittle; it typically has too much protein but lacks moisture, requiring moisture-rich products.

Normal Elasticity

Hair that stretches and returns to its normal shape without breakage, requiring products that provide a balanced ratio of protein and moisture.

High Elasticity

Hair that stretches excessively and fails to bounce back, indicating damage that requires protein-based products.

Hair Porosity

The ability of the hair strand to absorb moisture, categorized as low, medium, or high.

Nonporous Hair (Low Porosity)

Hair with a closed cuticle layer that is very healthy and shiny, resistant to chemicals, and exhibits slower absorption of chemicals and moisture.

Normal Porosity

Healthy hair characterized by a slightly raised cuticle layer that allows normal moisture absorption.

Porous Hair (High Porosity)

Damaged hair featuring an open or raised cuticle that is non-resistant to chemicals, processes faster, and loses moisture and artificial color rapidly.

Cantities

The technical term specified in the notes denoting grey hair.

Tricoptolosis

The technical term specified in the notes denoting split ends.

Scalp Analysis

An in-depth evaluation of the client's hair condition and scalp health prior to service to check for cuts, abrasions, abnormal hair loss from follicle inflammation, or contagious diseases (head lice, scabies, tinea/ringworm) that require declining service.