Have you ever thought about how the hair on your head can reach your waist, while hair in your arms appears to have a constant plateau? This question has been on the mind of nearly everyone who stands at the mirror in the bathroom. The answer isn’t in how frequently you trim your hair’s ends or in the kind of oil you use. It’s actually concealed underneath your skin, inside the tiny, intricate production facility called the hair follicle. Every hair in the body is currently travelling on its own, driven by the biological clock, which decides precisely when to develop and when to end the journey.Each hair strand is born in a hair Follicle. That is where magic occurs. At the base of this hair shaft, new hair cells rapidly grow in the root of the shaft. When these new cells are formed their own hair shaft, they behave as the conveyor belt of a soft one, moving the old cells up and away from the follicle. As they emerge from the skin’s surface, they are subjected to the process of keratinisation. They die, then become hardened and become the hair we have spent hours doing hairstyles and grooming. Since the hair visible is actually dead tissue, it can’t “heal” itself, which is why maintaining the well-being of the follicles at their root is important for keeping beautiful hair.The biological clock behind your growthThe reason why your eyebrows don’t grow is that your hair falls into a certain cycle called”the growth phase. The scientists refer to this time as the anagen phase. A follicle can produce cells for a certain duration based on its position on the body. When that time has passed, it enters the period of rest, also known as the”telogen” phase. The hair shaft breaks down or becomes pushed out, which causes natural shedding. The cycle is then re-established, and new, healthy hair begins to grow.The length of the growing phase is the main control of the length of your hair. The arm hair follicles have been genetically programmed to stop functioning every few months. It ensures that the hair on your arms remains small and easily manageable. Contrary to this, the hair follicles that you have on the scalp are designed to remain growing for a long time. This is why people are able to grow hair for decades without getting to a point where it stops. Based on a comprehensive review that was published in the Journal of Cell Science, the cycles are controlled by a complex signals that inform the hair follicle when to switch from growth to rest.
The duration of the growth phase determines hair length, with scalp follicles programmed for extended growth while arm hair follicles have shorter cycles. Image Credit: Gemini
Environmental adapters and the science of sheddingHumans shed hair in a sporadic, unpredictable manner. However, animals operate in a more coordinated manner. Animals that shed have hair in the hair follicles “in sync” with one another. As the seasons change, their follicles begin the rest phase in tandem, and hair begins to shed in huge clusters. This is a defence mechanism which allows them to swap their winter coats, which are heavy, for a light summer coat. In addition, several animals have the ability to switch the production of their pigment. In summer, the hair of animals is filled with melanin. This gives their hair an earthy or brown shade. With winter approaching, the follicles stop producing pigment completely. This results in an all-white coat, which provides perfect concealment against snow.Hair biology in humans is also dependent on our chemistry and our surrounding environment. An important study published within the International Journal of Molecular Sciences emphasises the way that various environmental factors, as well as cellular stressors, can influence the health of these hair follicles. Maintaining a healthy and safe environment for these small organs is vital, considering that the hair follicle is among the areas that are most active in metabolism in the human body. If we realise the fact that hair is an expression of those deep biological processes, it is easier to comprehend the intricate work that the body is doing every day to keep us safe and in control. If you spot a few hair strands within your hair, keep in mind that the follicles are clearing the way for a new start.
