Hair plays an important role in our lives. The hair on our head keeps us warm and acts as a cushion for our skull. Hair appearance can also help form our identity and self-image, which makes hair loss very troubling.
Most hair disorders aren’t serious, but they are often considered major cosmetic issues that require treatment. Androgenetic alopecia is the most common form of hair loss, although there are a number of other hair conditions that can affect the scalp and other parts of the body.
the three general classifications are sensory neurons, motor neurons and interneurons. I don't know how they work together to produce a response to an environmental stimulus:( sorry
100,000 years ago is your answer
Light is the energy source in Photosynthesis!
Hope this helped!
Automatically region nervous system
