Vellus hair, additionally known as peach fuzz, is the wonderful, skinny, light-colored hair that covers the vast majority of the physique, together with the face, arms, abdomen, and legs. Vellus hair additionally tends to be very brief and is normally now not than 2 millimeters. In Latin, vellus means “fleece” or “wool.”
One of many main capabilities of vellus hair is physique temperature regulation, significantly throughout chilly climate. Vellus hair is instrumental in perspiration. When a hair follicle is open, sweat coats the vellus hair after which evaporates, wicking away the sweat. Vellus hair additionally acts as a sensory perform of the pores and skin by alerting you if there’s an insect crawling in your arm and registering the feeling of goosebumps.
The one components of the physique that do not include hair follicles are the palms of the arms, the soles of the ft, behind the ears, the brow, eyelids, nostril, lips, the bellybutton, some components of the genitals and scar tissue.
Hair follicles exist inside the dermis—the second layer of pores and skin—they usually home stem cells, blood vessels, sebaceous glands, and hair. Vellus hair follicles, nevertheless, are not linked to sebaceous glands and due to this fact don’t produce sebum or oil. The hair inside the follicle is the dwelling a part of the hair. The hair you’ll be able to see is definitely useless.
Nearly all of hair on the human physique is vellus hair. Vellus hair is the hair that exists and grows throughout childhood, in contrast to terminal hair, which is influenced by hormones and seems throughout puberty.
How Puberty Impacts Hair Development
Hair progress is without doubt one of the many modifications that happens throughout puberty. Elevated hormone manufacturing—androgens, particularly—trigger vellus hair to show to terminal hair on sure components of the physique, together with the armpits and pubic space. The vellus hair, which was as soon as clean and light-weight, turns into coarser, darker and longer. The rise in androgens additionally causes hairs to develop subcutaneous glands that lubricate hair with oil, which is why puberty and zits go hand in hand.
Females are likely to retain extra vellus hair than males. Elevated hormone manufacturing throughout being pregnant can flip vellus hair into terminal hair, though that hair normally sheds as soon as the newborn is born and the feminine’s hormone ranges are again to regular. For males, terminal hair grows at a better price on extra components of the physique, together with the face, chest, again, legs, arms, arms, and ft.
Vellus Hair Circumstances
Generally vellus hair progress is irregular and generally is a signal of illness. For instance, elevated vellus hair progress could be attributed to an abundance of adrenal hormones within the bloodstream, a situation often called Cushing’s syndrome. Anorexia nervosa may enhance the manufacturing of vellus hair. The hormonal affect of androgens on hair follicles in circumstances of male sample baldness ends in a reversion of scalp hair from terminal to vellus hair.