The scientific definition of human hair is that, it is a biomaterial, which is filamentous in nature and is made from the protein keratin. It grows from follicles that are present on the human skin and is found in various types. Hair is basically the characteristic of the mammalian class, and functions to be a protective layer above the dermis or skin to protect it from external factors. Like mammals, the other classes of plant and animal kingdom have also developed certain hair like structures, that are filamentous and sensory, for protection of the bare dermis.
There are two structures that make up one hair filament and they are; the hair follicle/bulb, which is present beneath the skin, and the shaft, which is the visible hard filament above the skin (often known as hair). The color of these filaments are a result of two main types of hair pigments viz; eumelanin, that causes black, brown or dark blond hair colors, and pheomelanin causes red, blond and lighter colors. Colors of the hair also change when the levels of these pigments are decreased or innately less.
What are the Types of Human Hair
As humans, we have hair all over our body such as face, hands, legs, head, reproductive organs, etc., in order to protect these parts. Right from the time that a baby is developing inside the womb till it reaches puberty, there are various hair types that are seen growing on the body. Biologically, there are only three main types of human hair that are naturally formed by the body. These hair types are mentioned below, so read about these interesting classifications of human hair.
As mentioned above, people refer to their hair with respect to the pigmented hard filaments that extend out from the skin. This hair is called the terminal hair which grows on the dermis and is visible in various parts such as; head, hands, legs, armpits, face, pubic regions, etc. This hair type is known for the thickness, color and texture that varies depending on ethnicities.
You must have observed very fine and colorless hair shining in the light, sometimes when you pay close attention to your skin. This hair type is known as the vellus hair, which is found all over the body since birth. It is not distinctly visible but could get converted into terminal hair after puberty. The function of this hair is not protection, but regulation of body temperature, which can be related to the sensory function. The vellus hair is also called the "peach fuzz", and is a few millimeters long. It can be associated mainly to women and children as the vellus hair in men is changed to visible terminal hair.
When a baby is born, you will notice that its entire body is covered with hair which is long, thick and sometimes very strong. This is called the lanugo hair that covers the body of the baby when it is inside the womb to keep the skin hydrated and healthy. However, this hair is either replaced by vellus hair after the birth of the child, or it reduces with age.
Regional Hair Types
When we talk about human hair types, there are many variations that we come across. Many people often tend to classify these types depending on regional ethnicities such as Asian, African, Indian, European, etc. But these hair types are only based on stereotypical observations, as the individuals in these regions possess a typical form of hair.
Depending on these variations, African hair is usually found to be tight or softly coiled with a coarse hair or soft hair texture. Asian hair is however, pin straight and consists of dark hair strands, which grows faster than any other type of hair. Caucasian hair on the other hand is a mixture between African and Asian hair, and is denser than any other hair type. Generally, all these hair types respond to weather conditions like moisture, heat, cold, etc., in specific manners.