Vellus Hair: The Delicate and Unnoticeable Hair
When lanugo, the fine hair covering a newborn’s body, is shed, it is replaced by vellus hair. Vellus hair is characteristically short, light in color, and often goes unnoticed. Unlike other types of hair, vellus hair does not connect to a sebaceous gland. Although it is most prominent in children and adult women, vellus hair is commonly referred to as “peach fuzz,” especially in prepubescent males. Despite its delicate nature, vellus hair serves essential functions such as thermal insulation and cooling. As sweat from the body wets the vellus hairs, the evaporation of the sweat from the hair aids in regulating body temperature, providing a cooling effect.
Understanding Androgenic Hair
Androgenic hair, also known as terminal hair, refers to the thicker, longer, and darker hairs that replace vellus hair in certain parts of the body due to the presence of androgenic hormones like testosterone. This type of hair growth is commonly observed in areas such as the face, chest, abdomen, arms, feet, legs, pubic region, and armpits. Although androgenic hair follows a similar growth pattern to that of head hair, it has a shorter anagen phase (active growth phase) and a longer telogen phase (resting phase).
The primary purpose of androgenic hair is to provide sensory input through the longer and stronger hair strands. However, like head hair, androgenic hair has also become mainly cosmetic in nature.