About Hair

Hair is far more complex than it appears on the surface. We all know that it not only plays a vital role in the appearance of both men and women. Hair is much more complicated than it appears. It helps transmit sensory information and creates gender identity. Hair is important to the appearance of men and women. There is hair on all the major visible surfaces of the body. It is also the only body structure that is completely renewable without scarring. This article explains what exactly hair is and how it works. Hair is simple in structure, but has important functions in social functioning. Hair is made of a tough protein called keratin. A hair follicle anchors each hair into the skin. The hair bulb forms the base of the hair follicle. In the hair bulb, living cells divide and grow to build the hair shaft. Blood vessels nourish the cells in the hair bulb, and deliver hormones that modify hair growth and structure at different times of life.

Q: What is hair?
A: On our heads, we have hundreds of thousands of follicles, pore-like structures within the scalp that produce hair. Each follicle produces many hairs throughout our lifetime. Live hair cells are generated inside the follicle by the papilla. As the new cells grow, the older cells die and are forced along the follicle towards the scalp. The dead cells are compressed to form a protein called keratin. The hair shaft that we see is the keratin emerging from the scalp. Finger-nails are made of keratin, too.

Each hair consists of keratin, small amounts of water and a binding agent, which holds the keratin and water together.


Q: What is hair?
A: On our heads, we have hundreds of thousands of follicles, pore-like structures within the scalp that produce hair. Each follicle produces many hairs throughout our lifetime. Live hair cells are generated inside the follicle by the papilla. As the new cells grow, the older cells die and are forced along the follicle towards the scalp. The dead cells are compressed to form a protein called keratin. The hair shaft that we see is the keratin emerging from the scalp. Finger-nails are made of keratin, too.

Q: What is Hair Anatomy?
A: Hair has two separate structures - the follicle in the skin and the shaft we see. Follicle - The follicle is a stocking-like structure that contains several layers with different jobs. At the base of the follicle is a projection formed like sticking a finger in the bottom of a stocking and pushing it in a small amount. This projection is called a papilla and it contains capillaries, or tiny blood vessels, that feed the cells.
The living part of the hair is bottom part of the stocking surrounding the papilla called the bulb. This bottom part is the only part fed by the capillaries. The cells in the bulb divide every 23 to 72 hours, faster than any other cells in the body.
The follicle is surrounded by two sheaths - an inner and outer sheath.
These sheaths protect and mold the growing hair shaft. The inner sheath follows the hair shaft and ends below the opening of a sebaceous (oil) gland, and sometimes an apocrine (scent) gland. The outer sheath continues all the way up to the gland. A muscle called an erector pili muscle attaches below the gland to a fibrous layer around the outer sheath. When this muscle contracts, it causes the hair to stand up.
The sebaceous gland is important because it produces sebum which is a natural conditioner. More sebum is produced after puberty. The sebum production decreases in women throughout their lives. The production also decreases in men, but not as much as in women.
Shaft - The hair shaft is made up of dead, hard protein called keratin in three layers. The inner layer is called the medulla and may not be present. The next layer is the cortex and the outer layer is the cuticle. The cortex makes up the majority of the hair shaft. The cuticle is formed by tightly packed scales in an overlapping structure similar to roof shingles.
Most hair conditioning products attempt to affect the cuticle. There are pigment cells that are distributed throughout the cortex and medulla giving the hair its characteristic color.

Q: What are the Hair Follicles?
A: Hair has two distinct structures - first, the follicle itself, which resides in the skin, and second, the shaft, which is what, is visible above the scalp. The hair follicle is a tunnel-like segment of the epidermis that extends down into the dermis. The structure contains several layers that all have separate functions. At the base of the follicle is the papilla, which contains capillaries, or tiny blood vessels that nourish the cells. The living part of the hair is the very bottom part surrounding the papilla, called the bulb. The cells of the bulb divide every 23 to 72 hours, remarkably faster than any other cell in the body.
Two sheaths, an inner and outer sheath, surround the follicle. These structures protect and form the growing hair shaft. The inner sheath follows the hair shaft and ends below the opening of a sebaceous (oil) gland, and sometimes an apocrine (scent) gland.
The outer sheath continues all the way up to the gland. A muscle called an erector pili muscle attaches below the gland to a fibrous layer around the outer sheath. When this muscle contracts, it causes the hair to stand up which also causes the sebaceous gland to secrete oil.
The sebaceous gland is vital because it produces sebum, which conditions the hair and skin. After puberty our body produces more sebum but as we age we begin to make less sebum. Women have far less sebum production than men do as they age.

Q: What is hair Shaft?
A: The hair shaft is made of a hard protein called keratin and is made in three layers. This protein is actually dead, so the hair that you see is not a living structure. The inner layer is the medulla. The second layer is the cortex and the outer layer is the cuticle. The cortex makes up the majority of the hair shaft. The cuticle is a tightly formed structure made of shingle-like overlapping scales. It is both the cortex and the medulla that holds the hair's pigment, giving it its color.