Hair growth is a complex process controlled by hormones and genetics. Here's a simplified explanation:
1. The Hair Follicle: Hair starts in a tiny pocket in the skin called a hair follicle. This is where the growth happens.
2. The Bulb: At the base of the follicle is a bulb where hair cells are produced. This is like a hair factory.
3. The Matrix: Within the bulb is a special region called the matrix. This is where hair cells divide and grow.
4. Keratin: As new cells are produced, they fill with a protein called keratin. Keratin makes hair strong and flexible.
5. Growth Phase: New cells are constantly being made, pushing older cells upwards, causing the hair to grow longer.
6. Resting Phase: After a period of growth, the follicle enters a resting phase where no new cells are produced.
7. Shedding: Eventually, the old hair detaches and falls out. This is where we see hair "growing out" and needing a trim!
This process happens constantly, with different parts of the body having different growth cycles. For example, scalp hair grows much faster than eyebrow hair.