Does age impact hair growth rate and if so, why?
Grade 6
Presentation
No video provided
Hypothesis
I hypothesize that when you grow older your hair starts to lose its color, thickness and growth rate of your hair. I believe this because many people who are 45+ begin to start to have grey hair, hair loss and thin hair.
Research
Hair is a thin flexible structure that grows on the skin of every mammal. Like our nails our hair is mostly made of keratin. Our hair starts to grow underneath our skin in a tube-like-hole called a follicle. Individual pieces of hair have a shaft and root. The shaft is above a person's skin and this part of the hair is dead, which is why it doesn’t hurt to take a hair cut. On the other hand the root is below the skin's surface which contains living cells. In the base of each hair follicle there is something called a hair bulb which contains living hair cells. Blood vessels give the living cells nutrients which causes them to multiply making our hair grow. You have more than 100,000 hairs on your head and every day you lose about 50 to 100 while your combing your hair, taking a shower and even doing nothing. Each hair on your head grows for about 2-6 years then stays still for a couple months . When a piece of hair falls off, usually another piece of hair will grow in the same follicle to replace that strand of hair. As you grow older your anagen growing phase [the time when your hair shaft is the most active] becomes shorter. Some hair follicles also stop producing hair, resulting in thinner hair. Aging is a common cause of hair loss. You lose from about 50-100 hairs in a day in your life and it stays that way, but your hair growth starts to slow down. Stress can also cause hair loss to you and, it encourages it to you as you age. As you age your hair starts to lose it’s melanin [the cells that provide color to your hair] often giving people grey or white hair.
Variables
Controlled Variables:
Gender, period of time, materials used to measure hair and same part of hair on head measured.
Manipulated Variable:
The manipulated variable of my experiment is the different age groups.
Responding Variable:
My responding variable is the total length of hair grown by the participants in one week.