Hair is much more than a fashion tool, they are as much an indicator of your overall health as any part of your body. Actually our hair consists of different layers and structures. Each of those layers have different roles in shaping your final look. Here, we are providing you a quick look at the structure of human hair beyond its shiny outward appearance that we see day to day.
The integumentary system is an organ system that comprises of skin, hair, nails and exocrine glands. They act to protect the body from various kinds of damage, such as loss of water or abrasion from outside. This is what we are concentrating on today:
Integumentary system or the skin consist of mainly two layers, epidermis and dermis. The innermost layer, dermis is mostly made of dense irregular connective tissue along with nervous tissue, blood and blood vessels. Epidermis is the outermost layer which rests upon and protects the deeper and thicker dermis layer of the skin. Hair root is the part of hair just below the skin. Each hair arises from an indentation on the epidermis. Hair is made up of two parts, the hair follicle and hair shaft.
Follicle, the tube like depression in the scalp which contains the hair root, is the point from which hair grows. The lowest part of hair follicle is called the hair bulb and it is formed by actively growing cells that produce the long, fine cylindrical shaped hair fibres. The hair bulb also consists of special cells called melanocytes which produce the pigment that give hair its colour. This pigment-melanin also gives colour to the skin and eyes.
Another important part of hair follicle is dermal papilla- an indentation at the base of hair bulb which contains many blood vessels. It supplys nutrients to nourish the growing hair.
How many of you have heard of the oily substance called sebum which helps to lubricate our hair and skin? Sebaceous gland, adjacent to the hair follicle produces and secrets the natural oil which lubricates our hair.
The part of hair seen above the skin is called shaft. The hair shaft is made of three distinct layers: the cuticle, cortex and medulla.
Cuticle is the outermost layer or coating of the hair, made of Keratinocytes. They produce a protein called Keratin which hair and nails are comprised of. Keratin is the key structural material that makes up hair and outer layer of human skin. It also protects epithelial cells from damage or stress.
At the time of washing and styling, the cuticle will naturally break or become porous. Porosity is the hair’s ability to absorb and to retain moisture into the hair’s cuticle and cortex.
In low porosity hair, the cuticles will be closed, so moisture will not enter the hair easily. Though it feels like it, the cuticle are not actually damaged and most hair products are likely to stick around on the shaft. Low porosity hair will take a long time to dry.
You can make use of heated deep conditioners, it will help to open the cuticle and let the moisture in. Use hair dryers to heat the conditioner while it is on your hair.
In high porosity hair, the cuticles will absorb too much of moisture but will be unable to retain it. This will make your hair look dull and dry. These type of hair gets dry and frizzy quickly, not even needing a hair dryer most of the time.
Cortex is the middle layer of the hair shaft which provides strength and texture to the hair fibre. This thickest layer also contains melanin and other proteins that expresses your hair’s shape and colours respectively.
Hydrogen molecular bonds are responsible for maintaining natural shape of your hair. When it is permed, these bonds are disassembled, rearranged before the bonds return to their original shape, and fixed in their new position to create the new look.
The Medulla, deepest layer of the hair shaft, is not present in all hairs. The medulla can be seen only in thick and large hairs.
Hope the above information gives you a better understanding of your hair structure and in the process helps you take better care of it.