Hair 102: What makes up a hair follicle unit?
What makes up a hair follicle unit?
Every follicle in the scalp is associated with a sebaceous oil gland, eccrine sweat gland, arrector pili muscle (contracts to cause goosebumps), and a hair bulb which covers the dermal papilla. The dermal papilla is where a group of highly active matrix cells are located. These cells are responsible for producing the components that form hair fibers, including keratins, water, natural lipids (oil), and melanin pigments (eumelanin makes blonde to black color hair, phaeomelanin makes red hair).
Every hair follicle is associated with a sebaceous oil gland and an eccrine sweat gland. The sebaceous glands are hormone dependent and secrete sebum oil which provides a protective coating over the hair. This coat seals down the cuticle and provides an impermeable barrier on the hair. Sebum also provides gloss to the hair and protects against sun, wind, and daily styling and trauma the hair fibers endure. Eccrine sweat glands secrete water onto the scalp allowing for quick evaporation by heat escaping the scalp and is important for cooling the body down. It is important to know sweat is hypotonic salt is present and can cause drying and irritation to the scalp.
These units, known as follicular units, are harvested in their entirety for hair transplants. This enable the matrix/stem cells to have an intact structure to regrow a new hair once these follicles are implanted onto the scalp, eyebrows, beard hair, or other body parts.
Posted on: January 22, 2015, by : DrHillHairLoss