| Hair: properties, anatomy, growth |
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 Blonde ~ 150.000 Hairs |
 Brunette ~ 100.000 Haare |
 Red Hair ~ 80.000 Hairs |
 Black Hair ~ 110.000 Hairs |
The hair density of the scalp amounts therefore between 80 and 210 hairs per square centimeter. Apart from color of the hair it depends on the different scalp regions.
Body hair:
With the exception of a few regions, the whole surface of the human body is nearly covered by hair. However, only a small number of it (on the average, approximately 25,000) is
similarly well-developed like that of the scalp hair. This well-developed body hair is mostly to be found in different parts of the body: in the armpits, the pubic area, male breast and the lower leg.
Most of the body hair, however, is so small that one can barely see it with the naked eye. The fact is, the human body is greatly covered with hair. Exceptions to these are the palm of the hand and the sole of the foot.
Illustration 2 shows a close-up view of the normal lower eyelid region. One can clearly recognize among other structures the many tiny unpigmented hairs. There is around one million of this miniature hairs distributed all around the human body. The human being has basically the same number as that of a chimpanzee. There are some rare hereditary diseases, wherein miniature hairs are observed to grow intensively just like in the case of animals (Werewolf-syndrome).
Fig. 2: innumerable miniature hairs (=vellus hairs)
similarly well-developed like that of the scalp hair. This well-developed body hair is mostly to be found in different parts of the body: in the armpits, the pubic area, male breast and the lower leg.
Most of the body hair, however, is so small that one can barely see it with the naked eye. The fact is, the human body is greatly covered with hair. Exceptions to these are the palm of the hand and the sole of the foot.
Illustration 2 shows a close-up view of the normal lower eyelid region. One can clearly recognize among other structures the many tiny unpigmented hairs. There is around one million of this miniature hairs distributed all around the human body. The human being has basically the same number as that of a chimpanzee. There are some rare hereditary diseases, wherein miniature hairs are observed to grow intensively just like in the case of animals (Werewolf-syndrome).
Fig. 2: innumerable miniature hairs (=vellus hairs)
Types of hair
You have certainly found out already that hair can substantially differ from each other according to its characteristics.
Hair color is determined by the different kinds and number of melanin pigments. These pigment cells are called melanocytes and they lie very close to the hair bulb. They deliver their pigments to the new developing hair.
Beside hair color, there are also differences in the structure of hair. There is smooth hair, curly hair, strong hair, fine hair....
Belonging to the so-called terminal hairs are all thick and strong hairs. Examples of these are scalp hair, eyebrows, hair of the beard and pubic hair. Also well-developed hairs of the breast, the back and the extremities belong to this group.
All body hairs, which are fine, short and can only be recognized by taking a very close look belong to vellus hairs (examples are the fine hairs of the face as shown in the picture 2, and also the miniaturized hairs of the scalp, which occur in great numbers in a male with baldness in progress).
The so-called intermediate hairs show properties between a terminal and vellus hair. Examples of such type of hair are those hairs of the extremities, which are not so strong and well-developed.
Hair color is determined by the different kinds and number of melanin pigments. These pigment cells are called melanocytes and they lie very close to the hair bulb. They deliver their pigments to the new developing hair.
Beside hair color, there are also differences in the structure of hair. There is smooth hair, curly hair, strong hair, fine hair....
Belonging to the so-called terminal hairs are all thick and strong hairs. Examples of these are scalp hair, eyebrows, hair of the beard and pubic hair. Also well-developed hairs of the breast, the back and the extremities belong to this group.
All body hairs, which are fine, short and can only be recognized by taking a very close look belong to vellus hairs (examples are the fine hairs of the face as shown in the picture 2, and also the miniaturized hairs of the scalp, which occur in great numbers in a male with baldness in progress).
The so-called intermediate hairs show properties between a terminal and vellus hair. Examples of such type of hair are those hairs of the extremities, which are not so strong and well-developed.
