Getting to know your hair

Ever wonder why your hair doesn't all grow at the same time or same length, or shed at a certain season each year, like sheep and poodles? This is because each strand of human hair grows in its own random cycle, not according to a set season or cycle like some other animals. Here is a quick lesson on the different parts of your hair and how it grows.

Hair shaft: This is the part of the hair that you see on your head, under your arms, on your legs, in the pubic area, and on your face. It is the part of the hair that lies above the scalp, the part that we style, lather with shampoo, shave with shaving cream, dye, and perm. The hair shaft is made of keratin, a hard protein that is actually dead. In other words, the part of the hair that we see on the surface of our body is not a living structure.

Hair follicle: This is the part of the strand of hair that lies beneath the scalp. Each hair follicle stretches from the epidermis to the deeper layer in the skin, the dermis, and is made up of several layers. At the end of the hair follicle is the bulb, which is the living part of the hair. The bulb is surrounded by tiny blood vessels that nourish the cells of the bulb, causing the hair follicle to grow.

Hair growth cycle: Each strand of hair on our body grows in its own cycle, which is made up of three phases: anagen, catagen, and telogen.

  • Anagen is the active phase of hair growth. During this phase, hair grows about 1 cm every 28 days. Some people have difficulty growing their hair beyond a certain length because they have a short anagen phase. On the other hand, people with very long hair have a long anagen phase. The hairs on the arms, legs, eyelashes, and eyebrows have a very short anagen phase, which is why they are so much shorter than the hair on our head (also known as scalp hair). Scalp hair stays in this phase for 2 to 6 years. This is also the phase where colour pigment is made.
  • Catagen is a transitional stage, lasting about 2 to 3 weeks, when hair growth stops. About 3% of all hairs are in this phase at any one time.
  • Telogen is the resting phase. It lasts about 100 days for scalp hair and longer for hairs on your face, arms, and legs. During this phase, the hair follicle is completely at rest. About 25 to 100 telogen hairs are shed normally every day. This is also known as the "shedding phase."

How long your hair stays in the anagen phase is largely due to what you inherited from your parents. Unfortunately, even if you had aspirations to make it into the Guinness Book of World Records, you may simply not be born with the anagen chops of Xie Qiuping of Guangxi Province, China, who has held the record since 2004, with hair measuring in at 5.627 m (18' 5.54")!

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