Hair Structure

 

Hair is composed of strong structural protein called keratin which is the same kind of protein that makes up the nails andthe outer layer of skin. Each strand of hair consists of three layers:

1. Medulla – an innermost layer which is only present in large thick hairs.
2. Cortex – the middle layer which provides strength, color and the texture of hair.
3. Cuticle – the thin and colourless outermost layer which is serves as a protector of the cortex.

Structure Of The Hair Root

 

Below the surface of the skin is the hair root, which is enclosed within a hair follicle. At the base of the hair follicle is the dermal papilla. The dermal papilla is fed by the bloodstream which carries nourishment to produce new hair. The dermal papilla is a structure very important to hair growth because it contains receptors for male hormones and androgens. Androgens regulate hair growth and in scalp hair Androgens may cause the hair follicle to get progressively smaller and the hairs to become finer in individuals who are genetically predisposed to this type of hair loss.

Hair Growth Cycle

 


Ref: http://www.follicle.com/hair-structure-life-cycle.html

 

Hair follicles grow in repeated cycles. One cycle can be broken down into three phases:

1. Anagen - Growth Phase
2. Catagen - Transitional phase
3. Telogen - Resting Phase

Each hair passes through the phases independent of the neighboring hairs.

 

Anagen Phase - Growth Phase

 

Approximately 85% of all hairs are in the growing phase at any one time. The Anagen phase or growth phase can vary from two to six years. Hair grows approximately 10cm per year and any individual hair is unlikely to grow more than one meter long.

 

Catagen Phase - Transitional Phase

 

At the end of the Anagen phase the hairs enters into a Catagen phase which lasts about one or two weeks, during the Catagen phase the hair follicle shrinks to about 1/6 of the normal length. The lower part is destroyed and the dermal papilla breaks away to rest below.

 

Telogen Phase - Resting Phase

 

The resting phase follows the Catagen phase and normally lasts about 5-6 weeks. During this time the hair does not grow but stays attached to the follicle while the dermal papilla stays in a resting phase below. Approximately 10-15 percent of all hairs are in this phase at any one time. At the end of the Telogen phase, the hair follicle re-enters the Anagen phase. The dermal papilla and the base of the follicle join together again and a new hair begins to form. If the old hair has not already been shed the new hair pushes the old one out and the growth cycle starts all over again.

 

 

The Skin

 

 

 

Ginkgo Biloba has been widely used as a herbal remedy in treating thinning hair and hair loss. The skin is the body's largest organ, covering the entire outside of the body and weighing approximately six pounds. In addition to serving as a protective shield against heat, light, injury, and infection, the skin also:

• regulates body temperature
• stores water, fat, and vitamin D
• can sense painful and pleasant stimulation

Throughout the body, the skin's characteristics vary (i.e., thickness, color, texture). For instance, the head contains more hair follicles than anywhere else, while the soles of the feet contain none. In addition, the soles of the feet and the palms of the hands have much thicker layers.

The skin is made up of the following layers, with each layer performing specific functions:
• epidermis
• dermis
• fat layer