Before you can grow your hair, it’s essential to understand what hair is.
Hair is defined as any threadlike structure that grows from the skin.
Humans have two types of hair; vellus hair (short, fine hair that covers most parts of the body) and terminal hair (longer, coarser hair found on the scalp, face, armpits, pubic area, and other areas). Hair is made up primarily of the protein keratin.
Hair is a protein filament that grows from follicles found in the skin.
Each strand of hair consists of three layers: the medulla (the innermost layer), the cortex (the middle layer), and the cuticle (the outermost layer).
MEDULLA
The medulla is the innermost layer of the hair shaft, composed of loosely packed cells with air spaces between them.
CORTEX
The cortex makes up most of the hair shaft, and it’s responsible for giving hair its strength and elasticity. The pigment that gives our hair its color is also located in this layer.
CUTICLE
The cuticle is the outermost layer of the hair shaft, composed of overlapping scales that protect the inner layers from damage. The cuticle also helps to regulate moisture levels in the hair.
THE FUNCTION OF HAIR
There are several functions of human hair:
PROTECTION
Hair on our heads protects us from UV rays and physical trauma, such as cuts or scrapes to our scalp.
TEMPERATURE REGULATION
Hair can help regulate body temperature by entrapping heat close to our scalp or by allowing sweat to evaporate more easily.
SENSORY INPUT
Hair on our bodies can act as a sensory receptor when it’s moved or touched, and this can help us sense things like insects on our skin.
SOCIAL SIGNALING
Hair is often used as a means of communication in social situations. For example, hairstyles can signal things like status, personality, and cultural affiliation.
PIN IN FOR LATER
THE HAIR GROWTH CYCLE & HOW TO GROW YOUR HAIR LONG
The hair growth cycle has three phases: anagen (growth phase), catagen (transitional phase), and telogen (resting phase).
During anagen, cells in the follicle divide rapidly, resulting in new hair growth.
Catagen marks the end of active hair growth in which the follicle shrinks and detaches from the dermal papilla.
Finally, during telogen, old hairs fall out while new ones begin their growth cycle again.
Hair growth occurs in three phases:
ANAGEN PHASE
Also known as the growth phase, this is the period during which hair actively grows from the follicle. This phase can last anywhere from 2 to 7 years.
CATAGEN PHASE
During the catagen phase, hair growth slows down and eventually stops, and this phase only lasts about two weeks.
TELOGEN PHASE
The telogen phase is when hair rests in its follicle before being shed. This phase typically lasts around three months.
After the telogen phase ends, the anagen phase begins again, and a new hair shaft starts to grow.
OUR FINAL THOUGHTS ON WHAT IS HAIR? & HOW TO GROW NATURAL HAIR LONG
Hair is much more complex than just something growing out of our heads.
From its structure to function, a lot goes into making up these threadlike structures that we spend so much time cleaning, styling, and maintaining.
Understanding more about our own unique type of hair can lead to better care of it, as well as an appreciation for the role it plays in our lives.
Master your natural hair type today by downloading our hair growth guide here.