hair cycle


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Related to hair cycle: hair follicle, Telogen effluvium

hair cycle

[′her ‚sī·kəl]
(physiology)
The formation and growth of a new hair, followed by a resting stage, and ending with growth of another new hair from the same follicle.
References in periodicals archive ?
Stem cells in the bulge remain in the resting phase for most of their lives, but they can be activated depending on the hair cycle phase.
At the end of each hair cycle, some melanocytes become damaged and die.
PRP induced activation of anti-apoptotic regulators and prolongs the survival of dermal papilla cells during the hair cycle. [14,15] In addition, PRP treatment is suggested to stimulate hair growth by inducing follicular stem cell differentiation as well as prolonging the anagen phase of the hair growth cycle!1446 It also appears to increase the peri-follicular vascular plexus, through the increase of VEGF and PDGF levels, which have an angiogenic potential.
In the current study, we aimed to investigate the further molecular mechanism of deer antler aqueous extract on regulation of the hair cycle and hair follicle cell proliferation.
Study co-author Prof Colin Jahoda, in the School of Biological and Biomedical Sciences at Durham University, said: "We need to establish the origins of the critical intrinsic properties of the newly induced hairs, such as their hair cycle kinetics, colour, angle, positioning, and texture.
Readers who want additional medical information will appreciate the appendix where explanations include the hair cycle and details about several hair-loss conditions.
Proanthocyanidins from grape seeds promote proliferation of mouse hair follicle cells in vitro and convert hair cycle in vivo.
Many diseases are associated with hair cycle abnormalities, including endocrine diseases such as hypothyroidism and Cushing's syndrome; hereditary alopecia and hypotrichosis (the presence of less than normal amounts of hair); and familial zinc-responsive dermatopathy.
According to results presented at last year's annual meeting of the American Academy of Dermatology, a small-molecule hedgehog agonist, when topically applied to the skin, triggers the transition of hair follicles from the resting to growth phase of the hair cycle. The study's authors concluded that the topical application of a hedgehog agonist may be effective in treating such hair disorders as male pattern baldness and female hair loss.
This is the hair cycle and it has 3 stages: Anagen, is the active growth period and its length varies from one person to another, lasting about 1,000 days or more; Catagen is the resting or intermediate period, lasting about 10 days; Telogen is the shedding period, lasting about 100 days.