If you’re thinking that humans compared to other mammals are pretty hairless, then you are wrong. You may not notice but all over your body, except for the palms of your hands, soles of your feet and lips are big and small hairs. By the time one reach adulthood he’s likely to have around 5 million hairs on his skin.
Hair is composed of a special protein in your body called keratin, the same protein that can be found on your fingernails or toenails. Each and every strand of hair consists of these three concentric layers namely– the medulla, the cortex and the cuticle.
The medulla is the innermost layer of hair and is sometimes absent in very fine hair. The outermost layer is the cuticle. The cuticle is colorless and thin, the job of the cuticle is to protect the cortex and the melanin inside it. Melanin is gives color to your skin, eyes, and hair. The color of your hair depends on the kind of melanin you have . Melanin has two kinds, eumelanin, this is responsible for brown and black hair, or the pheomelanin which gives the hair an appearance of a reddish color, while low amounts of melanin results to giving a person their blond hair. If you are wondering what gives gray hair such color, it’s actually the lack of melanin often caused by stress, illness or old age.
The shape of your hair depends on the shape of the cortex. If you have straight hair then the cross section of the cortex is definitely round. If the cortex is oval you will have wavy or curly hair.
The thickness or length of your hair depends on what type it is. Fine fuzzy type of hair that usually sticks out is vellus hair. This type of hair is very, very fine and almost colorless and almost invisible to the naked eye.
The darker and more visible is the terminal hair. This is the hair that you physically refer to when you talk about your hair. Whether it’s the fine vellus or the thicker darker terminal, the health of your hair is dependent on the health of follicle that is producing your hair. When the follicle suffers physical damage it may not be able to produce terminal hair, and in turn produces vellus hair instead, this is the reason behind balding.
It is just normal for people to lose some of their hair. In fact, you lose several strands of hair per day. As old hair fall out they are replaced with new ones, but when you suffer from a hair loss condition your hair will thin out at a steady rate and can’t be replaced anymore. Depending on the cause, hair loss can either be temporary or permanent. Of course as with the rest of the body, hair will be healthy with the right diet, exercise, and protection from external factors like sun exposure.