one's hair grows long and thin
There are many kinds of hairs besides the hairs of the forehead. These include eyelashes, nose hairs, ear hairs, beards, and armpit hairs. However, even among these various types of hairs, they all have the same structure and growth pattern.
Hair is made up of two main parts. The first is the root-like part of the plant that is inside the skin, which is called the hair root. The other is the root-like part of the plant visible above the skin, which is called the hair shaft.
Hair is produced in the slightly swollen area at the base of the hair root. The hair root continues to produce new hairs for a long time, which makes the hairs in the hair shaft long and grow back even if they are cut off.
On the other hand, if the hair root stops making hairs too soon, they will not grow any longer. For example, eyelashes.
