Vellus hair is the fine, light-colored, and barely noticeable hair that covers most of the human body, helping regulate body temperature by providing a layer of insulation. Unlike terminal hair, vellus hair does not contain a medulla and is not involved in aesthetic or sexual functions, indicating its primary role is biological rather than social.

Vellus Hair

Fine Hair

Light-colored hair

Barely noticeable hair

Human body hair is a vestigial characteristic that primarily functions for protection and sensory input, varying in density and texture across different regions of the body. While its role has diminished with evolutionary advancements, hair still serves important biological and social functions, including thermoregulation and signaling puberty and maturity.

Human Body Hair

Body temperature regulation is a vital physiological process that maintains the body's core temperature within a narrow, optimal range despite external fluctuations. This homeostatic function involves complex interactions between the nervous, endocrine, and integumentary systems to balance heat production and dissipation.

Body Temperature Regulation

Layer of insulation

Terminal hair is the thick, coarse hair that develops on certain areas of the body during puberty and is usually darker and more pigmented compared to vellus hair. It plays a crucial role in thermoregulation and protection but can also be influenced by hormonal changes, genetics, and health conditions.

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