Karvoja

Karvoja is the Finnish term for hairs, the filamentous outgrowths of the skin that occur on humans and many animals. Hairs vary in length, thickness, color, and density and can be found across most of the body, with higher concentrations on the scalp, underarms, and pubic region.

Biologically, each hair grows from a follicle anchored in the dermis. The visible portion is the hair shaft, composed mainly of keratin, while the hair root resides below the skin. Pigment cells in the follicle give hair its color through melanin. The arrector pili muscle can raise hairs, producing a goosebumps effect.

Hair grows in cycles consisting of anagen (growth), catagen (transition), and telogen (resting) phases. The duration of these phases differs by body region and individual; scalp hairs can remain in anagen for several years, while body hairs have shorter cycles.

Different hair types exist: vellus hairs are fine and lightly pigmented; terminal hairs are longer, coarser, and more pigmented. Hormones, age, and health influence density and pattern; puberty promotes terminal hair growth in certain areas.

Medical and cosmetic considerations surround hair growth and loss. Conditions such as androgenetic alopecia (pattern hair loss) and hirsutism involve abnormal hair density or distribution. Treatments range from topical agents to medical and cosmetic interventions, depending on the condition.