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Illustration of a melanocyte Micrograph of melanocytes in the epidermis. Through a process called melanogenesis, melanocytes produce melanin, which is a pigment found in the skin, eyes, hair, nasal cavity, and inner ear. This melanogenesis leads to a long-lasting pigmentation, which is in contrast to the pigmentation that originates from ...
Humans over the age of thirty experience a decrease in melanin-producing cells by about 10% to 20% per decade as melanocyte stem cells gradually die. [109] The skin of face and hands has about twice the amount of pigment cells as unexposed areas of the body, as chronic exposure to the sun continues to stimulate melanocytes.
Melanocytes insert granules of melanin into specialized cellular vesicles called melanosomes. These are then transferred into the keratinocyte cells of the human epidermis . The melanosomes in each recipient cell accumulate atop the cell nucleus , where they protect the nuclear DNA from mutations caused by the ionizing radiation of the sun's ...
The human skin is the outer covering of the body and is the largest organ of the ... 60,000 melanocytes, and more than 1,000 nerve endings. [5] [better ...
The melanocyte-stimulating hormones, known collectively as MSH, also known as melanotropins or intermedins, are a family of peptide hormones and neuropeptides consisting of α-melanocyte-stimulating hormone (α-MSH), β-melanocyte-stimulating hormone (β-MSH), and γ-melanocyte-stimulating hormone (γ-MSH) that are produced by cells in the pars intermedia of the anterior lobe of the pituitary ...
MCH is a cyclic 19-amino acid neuropeptide, as it is a polypeptide chain that is able to act as a neurotransmitter.MCH neurons are mainly concentrated in the lateral hypothalamic area, zona incerta, and the incerto-hypothalamic area, but they are also located, in much smaller amounts, in the paramedian pontine reticular formation (PPRF), medial preoptic area, laterodorsal tegmental nucleus ...
A study links graying hair to stem cells getting stuck, unable to color new hair growth. And here's the good news: That might mean gray hair is reversible.
The pseudopodial process (aka the tanning process) happens slowly in dermal melanocytes in response to ultraviolet light and to production of new melanosomes and increased donation of melanosomes to adjacent keratinocytes, which are typical skin surface cells. Donation occurs when some keratinocytes engulf the end of the melanocyte pseudopodia ...