There are several reasons why people lose their hair and require medical hair restoration. The hereditary factor predominates in cases of male pattern baldness, though stress too can play a role. That is when hair transplantation, a highly effective method of medical hair restoration, becomes necessary.
Hair consists of two parts – the hair follicle and the hair shaft – and is composed of a protein called keratin. Each hair strand has three layers. The innermost layer, or modula, is found in large thick hair. The cortex – or the middle layer – gives the hair its strength, color and texture. The outermost layer, called cuticle, protects the cortex.
Structure of hair root
The hair root is enclosed within the hair follicle, and the dermal papilla lie at its base. The root is nourished by the bloodstream, which is how new hair sprout up. Herein lie also the receptors for the male hormones and the androgens that are crucial for hair growth. The androgens, which regulate hair growth, can cause the hair follicle to progressively shrink, causing the hair to thin down in people who are genetically predisposed to hair loss.
The hair follicle is a sac-like structure. Hair grows out of the follicle, into which the sebaceous glands also open. The hair follicle grows by packing old cells together. The sebaceous gland, a sebum-producing gland, is attached to the hair follicle. Having thick hair implies an abundance of sebaceous glands that are absent from the palms, lips and soles.
A tiny bundle of muscle fiber called arrector pili is also attached to the hair follicles. The arrector pili causes the follicle and hair to rise perpendicularly to the skin surface. Hair follicles grow at the rate of .04 cm per day.
What is dermal papilla?
The dermal papilla, a small structure based at the root of the hair follicle, is made up of connective tissue and a capillary loop. There is no cell division in the papilla, around which is the hair matrix – a collection of epithelial cells that are often interspersed with melanocytes. The cell division in the hair matrix enables formation of the hair fiber and the inner root sheath. The hair matrix epithelium is a fast-growing cell population in the human body, and the papilla is normally pear-shaped with the matrix wrapped completely around it.
The hair follicle consists of two parts. The hair bulb inside it produces the long fine cylinder of hair. New cells are continuously being produced in the lower part of the hair bulb. As it develops it steadily pushes the previously formed cells upwards. Once a cell reaches the upper part of the bulb it gets transformed into six cylindrical layers – the three layers in its inner side becoming the actual hair.
Special cells in the hair bulb, called melanocytes, produce the pigment called melanin, which gives the hair its color.