Hair

Hair Growth Rate.

Hair grows at a speed of approximately 1 cm per month.

Daily Hair Loss.

On average, a person loses about 100-150 hairs per day.

Weight of Hair.

The weight of hair on a human head ranges from 5 to 200 grams depending on hair length.

Hair Structure

Hair is composed of three main parts: the cuticle, cortex, and medulla.

Cuticle Function

The cuticle protects the cortex, maintains hair appearance, and limits friction between hair fibers.

Hair Porosity Test

To test hair porosity, place clean, shed hair in room temperature water: high porosity sinks, medium suspends, low floats.

Cuticle Layer Thickness

Each cuticle layer is about 60 microns long and 0.5 microns thick.

Elastic Properties of Hair

Hair can stretch up to 20% of its original length when dry and up to 50% when wet before breaking.

Number of Hairs on Scalp

An average human scalp contains about 100,000 hairs.

Function of Hair

Hair serves multiple functions including protection, appearance, and insulation.

Cortical Cells

The cortex is primarily made up of elongated, proteinaceous cells called cortical cells, responsible for hair elasticity.

Cell Membrane Complex (CMC)

A lipid material that acts as intercellular cement to glue together cuticle layers and protect the hair.

Hair Follicle Components

A hair follicle consists of an outer root sheath, inner root sheath, and hair bulb.

Types of Cortical Cells

There are two types of cortical cells: para cortical (uniform shape) and ortho cortical (non-uniform shape).

Conditioners for Hair

Conditioners with an acidic nature help to close the hair cuticle after washing.

Effects of Alkaline Products on Hair

Alkaline products can cause hair swelling and cuticle opening, resulting in frizzy and brittle hair.

Strength of Hair

Hair can withstand a weight of up to 100 grams for a single strand.

Hair Cuticle Integrity

Intact and closed cuticles protect hair moisture and appearance; open cuticles can lead to damage.

Ribbon-like Architecture of Hair

Hair shaft is structured similarly to a pencil, composed of several layered components.

Sebum

A natural oil produced by sebaceous glands that helps to seal hair cuticles.

What are the functions of hair on the human body?

Hair serves multiple essential functions, including:

1. Protection: Hair shields the scalp and skin from harmful UV radiation, minimizing risks of sunburn and skin damage.
2. Insulation: It helps maintain body warmth by trapping heat, effectively regulating body temperature in cooler environments.
3. Sensory Perception: Hair follicles are linked to nerve endings, making hair sensitive to light touch and environmental changes.
4. Evaporation Assistance: Hair contributes to the evaporation of sweat, which is vital for cooling the body in hot conditions.