Terminal Hair vs. Vellus Hair

Attribute	Terminal Hair	Vellus Hair
Definition	Coarse, pigmented hair that grows on the scalp, face, armpits, and pubic region	Fine, unpigmented hair that covers most of the body surface
Length	Longer	Shorter
Diameter	Thicker	Thinner
Pigmentation	Pigmented	Unpigmented
Growth Rate	Slower	Faster
Location	Scalp, face, armpits, pubic region	Most of the body surface
Function	Protection, insulation, sensory perception	Thermoregulation, tactile sensation

Introduction

Hair is a fascinating and complex part of our body that serves various functions. It not only protects our skin from external factors but also plays a role in regulating body temperature. There are different types of hair found on our bodies, including terminal hair and vellus hair. In this article, we will explore the attributes of these two types of hair and understand their differences.

Terminal Hair

Terminal hair is the type of hair that most people are familiar with. It is thick, long, and pigmented, and it is found in areas such as the scalp, eyebrows, and armpits. Terminal hair is characterized by its ability to grow to a considerable length and its relatively high rate of growth. It is also more deeply rooted in the hair follicles compared to vellus hair.

One of the primary functions of terminal hair is to provide insulation and protection. For example, the hair on our scalp helps to regulate body temperature by providing a layer of insulation. Additionally, terminal hair on the eyebrows and eyelashes helps to protect our eyes from dust, debris, and sweat.

Terminal hair is also influenced by hormones, particularly androgens such as testosterone. During puberty, the increase in androgen levels triggers the growth of terminal hair in areas such as the face, chest, and pubic region. This is why males typically have more terminal hair than females.

Furthermore, terminal hair has a longer growth cycle compared to vellus hair. This means that it can grow for a longer period before entering the resting phase and eventually falling out. The growth cycle of terminal hair can vary between individuals, but on average, it can grow for several years before being replaced by a new hair strand.

In terms of appearance, terminal hair is usually darker and coarser compared to vellus hair. It contains more pigment, which gives it its characteristic color. The thickness of terminal hair is also due to the larger diameter of the hair shaft. These attributes make terminal hair more noticeable and prominent on the body.

Vellus Hair

Vellus hair, on the other hand, is much finer, shorter, and lighter in color compared to terminal hair. It is commonly found on areas of the body where terminal hair is absent or minimal, such as the cheeks, back, and arms. Vellus hair is less deeply rooted in the hair follicles and has a shorter growth cycle compared to terminal hair.

Unlike terminal hair, vellus hair does not have a significant role in insulation or protection. It is more delicate and serves primarily as a sensory function, providing us with a heightened sense of touch. For example, the vellus hair on our face helps us detect subtle changes in the environment, such as a gentle breeze or a light touch.

Vellus hair is not influenced by androgens to the same extent as terminal hair. It remains relatively unchanged throughout a person's life, regardless of hormonal fluctuations. This is why both males and females have similar amounts of vellus hair in most areas of their bodies.

Another characteristic of vellus hair is its shorter growth cycle. It grows for a shorter period before entering the resting phase and eventually shedding. This is why vellus hair does not reach the same length as terminal hair. The growth cycle of vellus hair can vary between individuals, but on average, it grows for a few months before being replaced.

Visually, vellus hair is less noticeable compared to terminal hair due to its fine texture and light color. It blends in with the surrounding skin, making it less prominent. However, it still plays a crucial role in maintaining the overall health and function of our skin.

Conclusion

In conclusion, terminal hair and vellus hair are two distinct types of hair found on our bodies. Terminal hair is thick, long, and pigmented, while vellus hair is fine, short, and light in color. Terminal hair serves functions such as insulation and protection, influenced by hormones and having a longer growth cycle. On the other hand, vellus hair has a sensory function, remains relatively unchanged throughout life, and has a shorter growth cycle. Understanding the attributes of these two types of hair helps us appreciate the complexity and diversity of our hair and its role in our overall well-being.