158 relations: Accommodation (eye), Adrenal gland, Adrenal medulla, Africa, African Americans, Agouti (gene), Albinism, Albinism in biology, Amino acid, Amish, Antioxidant, Apoptosis, Aposematism, Arachnid, Archaic human admixture with modern humans, Archaic humans, Arthropod, Asia, Benzothiazine, Benzothiazole, Bird, Birth defect, Brain, Brainstem, Carboxylic acid, Carotenoid, Catechol, Catecholamine, Catecholaminergic, Cell nucleus, Cephalopod, Cephalopod ink, Charles Darwin, Chelation, Choroid, Cochlea, Copolymer, Covalent bond, Cryptococcus neoformans, Cysteine, Denisovan, DHICA, Distributed Bragg reflector, DNA, Dopachrome, Dopamine, Downregulation and upregulation, Enzyme catalysis, Epidermis, Equator, ..., Europe, Eye color, Feather, Ferulic acid, Folate, Food browning, Fovea centralis, Freckle, Gamma ray, Germany, Griscelli syndrome, Hair, Health effects of sunlight exposure, Hearing loss, Heavy metals, Hemosiderin, High-energy visible light, Homo sapiens, Hopi, Host (biology), Human skin color, Immune system, Indirect DNA damage, Indole, Indole-5,6-quinone, Inner ear, Ionizing radiation, Iridescence, Iris (anatomy), KEGG, Keratin, Keratinocyte, L-DOPA, L-Dopaquinone, Locus coeruleus, Macular degeneration, Mammal, Melanin, Melanin theory, Melanism, Melanocortin 1 receptor, Melanocyte, Melanoma, Melanosome, Metabolic pathway, Molecular mass, Monomer, Neanderthal, Neuromelanin, Nevus, Nicotine, Norepinephrine, North America, Oculocutaneous albinism, On the Origin of Species, Organism, Oxidizing agent, Parasemia plantaginis, Parkinson's disease, Pathogen, PH, Phagocytosis, Photodegradation, Photoprotection, Photosynthetic pigment, Pigment, Polymerization, Polyphenol oxidase, Port-wine stain, Potassium permanganate, Primate, Pro-oxidant, Protein, Quinone, Radiotrophic fungus, Rasagiline, Reactive oxygen species, Red hair, Redox, Retinal pigment epithelium, Riboflavin, Rickets, Rod cell, Signal transduction, Skin cancer, Skin whitening, SLC24A5, Smoking cessation, Solar irradiance, Stratum basale, Stria vascularis of cochlear duct, Structural coloration, Substantia nigra, Sun tanning, Sunburn, Switzerland, Tocopherol, Transition metal, Tyrosinase, Tyrosine, Ultraviolet, Vesicle (biology and chemistry), Viral matrix protein, Virulence, Vitamin, Vitamin D, Waardenburg syndrome, Zona reticularis. Expand index (108 more) » « Shrink index
Accommodation is the process by which the vertebrate eye changes optical power to maintain a clear image or focus on an object as its distance varies.
The adrenal glands (also known as suprarenal glands) are endocrine glands that produce a variety of hormones including adrenaline and the steroids aldosterone and cortisol.
The adrenal medulla (medulla glandulae suprarenalis) is part of the adrenal gland.
Africa is the world's second largest and second most-populous continent (behind Asia in both categories).
African Americans (also referred to as Black Americans or Afro-Americans) are an ethnic group of Americans with total or partial ancestry from any of the black racial groups of Africa.
agouti is a gene that controls the distribution of the natural pigment, melanin, in the hair of mammals and helps determine their coat color patterns.
Albinism in humans is a congenital disorder characterized by the complete or partial absence of pigment in the skin, hair and eyes.
Albinism in biology is the "Congenital absence of any pigmentation or coloration in a person, animal or plant, resulting in white hair and pink eyes in mammals." Varied use and interpretation of the terms mean that written reports of albinistic animals can be difficult to verify.
Amino acids are organic compounds containing amine (-NH2) and carboxyl (-COOH) functional groups, along with a side chain (R group) specific to each amino acid.
The Amish (Pennsylvania German: Amisch, Amische) are a group of traditionalist Christian church fellowships with Swiss German Anabaptist origins.
Antioxidants are molecules that inhibit the oxidation of other molecules.
Apoptosis (from Ancient Greek ἀπόπτωσις "falling off") is a process of programmed cell death that occurs in multicellular organisms.
Aposematism (from Greek ἀπό apo away, σῆμα sema sign) is a term coined by Edward Bagnall PoultonPoulton, 1890.
Arachnids are a class (Arachnida) of joint-legged invertebrate animals (arthropods), in the subphylum Chelicerata.
There is evidence for interbreeding between archaic and modern humans during the Middle Paleolithic and early Upper Paleolithic.
A number of varieties of Homo are grouped into the broad category of archaic humans in the period contemporary and predating the emergence of the earliest anatomically modern humans (Homo sapiens) over 315 kya.
An arthropod (from Greek ἄρθρον arthron, "joint" and πούς pous, "foot") is an invertebrate animal having an exoskeleton (external skeleton), a segmented body, and paired jointed appendages.
Asia is Earth's largest and most populous continent, located primarily in the Eastern and Northern Hemispheres.
Benzothiazine is a heterocyclic compound consisting of a benzene ring attached to the 6-membered heterocycle thiazine.
Benzothiazole is an aromatic heterocyclic compound with the chemical formula.
Birds, also known as Aves, are a group of endothermic vertebrates, characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweight skeleton.
A birth defect, also known as a congenital disorder, is a condition present at birth regardless of its cause.
The brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals.
The brainstem (or brain stem) is the posterior part of the brain, adjoining and structurally continuous with the spinal cord.
A carboxylic acid is an organic compound that contains a carboxyl group (C(.
Carotenoids, also called tetraterpenoids, are organic pigments that are produced by plants and algae, as well as several bacteria and fungi.
Catechol, also known as pyrocatechol or 1,2-dihydroxybenzene, is an organic compound with the molecular formula C6H4(OH)2.
A catecholamine (CA) is a monoamine, an organic compound that has a catechol (benzene with two hydroxyl side groups at carbons 1 and 2) and a side-chain amine.
Catecholaminergic means "related to catecholamines".
In cell biology, the nucleus (pl. nuclei; from Latin nucleus or nuculeus, meaning kernel or seed) is a membrane-enclosed organelle found in eukaryotic cells.
A cephalopod is any member of the molluscan class Cephalopoda (Greek plural κεφαλόποδα, kephalópoda; "head-feet") such as a squid, octopus or nautilus.
Cephalopod ink is a dark pigment released into water by most species of cephalopod, usually as an escape mechanism.
Charles Robert Darwin, (12 February 1809 – 19 April 1882) was an English naturalist, geologist and biologist, best known for his contributions to the science of evolution.
Chelation is a type of bonding of ions and molecules to metal ions.
The choroid, also known as the choroidea or choroid coat, is the vascular layer of the eye, containing connective tissues, and lying between the retina and the sclera.
The cochlea is the part of the inner ear involved in hearing.
When two or more different monomers unite together to polymerize, the product is called a copolymer and the process is called copolymerization.
A covalent bond, also called a molecular bond, is a chemical bond that involves the sharing of electron pairs between atoms.
Cryptococcus neoformans is an encapsulated yeast and an obligate aerobe that can live in both plants and animals.
Cysteine (symbol Cys or C) is a semi-essential proteinogenic amino acid with the formula HO2CCH(NH2)CH2SH.
The Denisovans or Denisova hominins) are an extinct species or subspecies of archaic humans in the genus Homo.
DHICA (5,6-dihydroxyindole-2-carboxylic acid) is an intermediate in the biosynthesis of melanin.
A distributed Bragg reflector (DBR) is a reflector used in waveguides, such as optical fibers.
Deoxyribonucleic acid (DNA) is a thread-like chain of nucleotides carrying the genetic instructions used in the growth, development, functioning and reproduction of all known living organisms and many viruses.
Dopachrome is a cyclization product of L-DOPA and is an intermediate in the biosynthesis of melanin.
Dopamine (DA, a contraction of 3,4-dihydroxyphenethylamine) is an organic chemical of the catecholamine and phenethylamine families that plays several important roles in the brain and body.
In the biological context of organisms' production of gene products, downregulation is the process by which a cell decreases the quantity of a cellular component, such as RNA or protein, in response to an external stimulus.
Enzyme catalysis is the increase in the rate of a chemical reaction by the active site of a protein.
The epidermis is the outer layer of the three layers that make up the skin, the inner layers being the dermis and hypodermis.
An equator of a rotating spheroid (such as a planet) is its zeroth circle of latitude (parallel).
Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere.
Eye color is a polygenic phenotypic character determined by two distinct factors: the pigmentation of the eye's iris and the frequency-dependence of the scattering of light by the turbid medium in the stroma of the iris.
Feathers are epidermal growths that form the distinctive outer covering, or plumage, on birds and other, extinct species' of dinosaurs.
Ferulic acid is a hydroxycinnamic acid, an organic compound.
Folate, distinct forms of which are known as folic acid, folacin, and vitamin B9, is one of the B vitamins.
Browning is the process of food turning brown due to the chemical reactions that take place within.
The fovea centralis is a small, central pit composed of closely packed cones in the eye.
Freckles are clusters of concentrated melaninized cells which are most easily visible on people with a fair complexion.
A gamma ray or gamma radiation (symbol γ or \gamma), is penetrating electromagnetic radiation arising from the radioactive decay of atomic nuclei.
Germany (Deutschland), officially the Federal Republic of Germany (Bundesrepublik Deutschland), is a sovereign state in central-western Europe.
Griscelli syndrome is a rare autosomal recessive disorder characterized by albinism (hypopigmentation) with immunodeficiency, that usually causes death by early childhood.
Hair is a protein filament that grows from follicles found in the dermis.
The ultraviolet radiation in sunlight has both positive and negative health effects, as it is both a principal source of vitamin D3 and a mutagen.
Hearing loss, also known as hearing impairment, is a partial or total inability to hear.
Heavy metals are generally defined as metals with relatively high densities, atomic weights, or atomic numbers.
Hemosiderin image of a kidney viewed under a microscope. The brown areas represent hemosiderin Hemosiderin or haemosiderin is an iron-storage complex.
In ophthalmology, high-energy visible light (HEV light) is high-frequency, high-energy light in the violet/blue band from 400 to 450 nm in the visible spectrum.
Homo sapiens is the systematic name used in taxonomy (also known as binomial nomenclature) for the only extant human species.
The Hopi are a Native American tribe, who primarily live on the Hopi Reservation in northeastern Arizona.
In biology and medicine, a host is an organism that harbours a parasitic, a mutualistic, or a commensalist guest (symbiont), the guest typically being provided with nourishment and shelter.
Human skin color ranges in variety from the darkest brown to the lightest hues.
The immune system is a host defense system comprising many biological structures and processes within an organism that protects against disease.
Indirect DNA damage occurs when a UV-photon is absorbed in the human skin by a chromophore that does not have the ability to convert the energy into harmless heat very quickly.
Indole is an aromatic heterocyclic organic compound with formula C8H7N.
Indole-5,6-quinone is an indolequinone, a chemical compound found in the oxidative browning reaction of fruits like bananas where it is mediated by the tyrosinase type polyphenol oxidase from tyrosine and catecholamines leading to the formation of catechol melanin.
The inner ear (internal ear, auris interna) is the innermost part of the vertebrate ear.
Ionizing radiation (ionising radiation) is radiation that carries enough energy to liberate electrons from atoms or molecules, thereby ionizing them.
Iridescence (also known as goniochromism) is the phenomenon of certain surfaces that appear to gradually change colour as the angle of view or the angle of illumination changes.
In humans and most mammals and birds, the iris (plural: irides or irises) is a thin, circular structure in the eye, responsible for controlling the diameter and size of the pupil and thus the amount of light reaching the retina.
KEGG (Kyoto Encyclopedia of Genes and Genomes) is a collection of databases dealing with genomes, biological pathways, diseases, drugs, and chemical substances.
Keratin is one of a family of fibrous structural proteins.
A keratinocyte is the predominant cell type in the epidermis, the outermost layer of the skin, constituting 90% of the cells found there.
L-DOPA, also known as levodopa or L-3,4-dihydroxyphenylalanine is an amino acid that is made and used as part of the normal biology of humans, as well as some animals and plants.
L-Dopaquinone also known as o-dopaquinone is a metabolite of L-DOPA and a precursor of melanin.
The locus coeruleus (\-si-ˈrü-lē-əs\, also spelled locus caeruleus or locus ceruleus) is a nucleus in the pons of the brainstem involved with physiological responses to stress and panic.
Macular degeneration, also known as age-related macular degeneration (AMD or ARMD), is a medical condition which may result in blurred or no vision in the center of the visual field.
Mammals are the vertebrates within the class Mammalia (from Latin mamma "breast"), a clade of endothermic amniotes distinguished from reptiles (including birds) by the possession of a neocortex (a region of the brain), hair, three middle ear bones, and mammary glands.
Melanin (from μέλας melas, "black, dark") is a broad term for a group of natural pigments found in most organisms.
Melanin theory is a claim in Afrocentrism that a higher level of melanin, the primary determinant of skin color in humans, is the cause of an intellectual and physical superiority of dark-skinned people and provides them with supernatural powers.
Melanism is a development of the dark-colored pigment melanin in the skin or its appendages and is the opposite of albinism.
The melanocortin 1 receptor (MC1R), also known as melanocyte-stimulating hormone receptor (MSHR), melanin-activating peptide receptor, or melanotropin receptor, is a G protein–coupled receptor that binds to a class of pituitary peptide hormones known as the melanocortins, which include adrenocorticotropic hormone (ACTH) and the different forms of melanocyte-stimulating hormone (MSH).
Melanocytes are melanin-producing neural crest-derived cells located in the bottom layer (the stratum basale) of the skin's epidermis, the middle layer of the eye (the uvea), the inner ear, vaginal epithelium, meninges, bones, and heart.
Melanoma, also known as malignant melanoma, is a type of cancer that develops from the pigment-containing cells known as melanocytes.
A melanosome is an organelle found in animal cells and is the site for synthesis, storage and transport of melanin, the most common light-absorbing pigment found in the animal kingdom.
In biochemistry, a metabolic pathway is a linked series of chemical reactions occurring within a cell.
Relative Molecular mass or molecular weight is the mass of a molecule.
A monomer (mono-, "one" + -mer, "part") is a molecule that "can undergo polymerization thereby contributing constitutional units to the essential structure of a macromolecule".
Neanderthals (also; also Neanderthal Man, taxonomically Homo neanderthalensis or Homo sapiens neanderthalensis) are an extinct species or subspecies of archaic humans in the genus Homo, who lived in Eurasia during at least 430,000 to 38,000 years ago.
Neuromelanin (NM) is a dark pigment found in the brain which is structurally related to melanin.
Nevus (or nevi if multiple) is a nonspecific medical term for a visible, circumscribed, chronic lesion of the skin or mucosa.
Nicotine is a potent parasympathomimetic stimulant and an alkaloid found in the nightshade family of plants.
Norepinephrine (NE), also called noradrenaline (NA) or noradrenalin, is an organic chemical in the catecholamine family that functions in the brain and body as a hormone and neurotransmitter.
North America is a continent entirely within the Northern Hemisphere and almost all within the Western Hemisphere; it is also considered by some to be a northern subcontinent of the Americas.
Oculocutaneous albinism (OCA) is a form of albinism involving the eyes (oculo-), the skin (-cutaneous), and according to some definitions, the hair.
On the Origin of Species (or more completely, On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life),The book's full original title was On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life.
In biology, an organism (from Greek: ὀργανισμός, organismos) is any individual entity that exhibits the properties of life.
In chemistry, an oxidizing agent (oxidant, oxidizer) is a substance that has the ability to oxidize other substances — in other words to cause them to lose electrons.
Parasemia plantaginis, the wood tiger, is a moth of the family Erebidae.
Parkinson's disease (PD) is a long-term degenerative disorder of the central nervous system that mainly affects the motor system.
In biology, a pathogen (πάθος pathos "suffering, passion" and -γενής -genēs "producer of") or a '''germ''' in the oldest and broadest sense is anything that can produce disease; the term came into use in the 1880s.
In chemistry, pH is a logarithmic scale used to specify the acidity or basicity of an aqueous solution.
In cell biology, phagocytosis is the process by which a cell—often a phagocyte or a protist—engulfs a solid particle to form an internal compartment known as a phagosome.
Photodegradation is the alteration of materials by light.
Photoprotection is the biochemical process that helps organisms cope with molecular damage caused by sunlight.
A photosynthetic pigment (accessory pigment; chloroplast pigment; antenna pigment) is a pigment that is present in chloroplasts or photosynthetic bacteria and captures the light energy necessary for photosynthesis.
A pigment is a material that changes the color of reflected or transmitted light as the result of wavelength-selective absorption.
In polymer chemistry, polymerization is a process of reacting monomer molecules together in a chemical reaction to form polymer chains or three-dimensional networks.
Polyphenol oxidase (PPO; also monophenol monooxygenase or polyphenol oxidase i, chloroplastic) is a tetramer that contains four atoms of copper per molecule, and binding sites for two aromatic compounds and oxygen.
A port-wine stain (nevus flammeus), also commonly called a firemark, is a discoloration of the human skin caused by a vascular anomaly (a capillary malformation in the skin).
Potassium permanganate is an inorganic chemical compound and medication.
A primate is a mammal of the order Primates (Latin: "prime, first rank").
Pro-oxidants are chemicals that induce oxidative stress, either by generating reactive oxygen species or by inhibiting antioxidant systems.
Proteins are large biomolecules, or macromolecules, consisting of one or more long chains of amino acid residues.
The quinones are a class of organic compounds that are formally "derived from aromatic compounds by conversion of an even number of –CH.
Radiotrophic fungi are fungi which appear to perform radiosynthesis, that is, to use the pigment melanin to convert gamma radiation into chemical energy for growth.
Rasagiline (Azilect, TVP-1012, N-propargyl-1(R)-aminoindan) is an irreversible inhibitor of monoamine oxidase-B used as a monotherapy to treat symptoms in early Parkinson's disease or as an adjunct therapy in more advanced cases.
Reactive oxygen species (ROS) are chemically reactive chemical species containing oxygen.
Red hair (or ginger hair) occurs naturally in 1–2% of the human population.
Redox (short for reduction–oxidation reaction) (pronunciation: or) is a chemical reaction in which the oxidation states of atoms are changed.
The pigmented layer of retina or retinal pigment epithelium (RPE) is the pigmented cell layer just outside the neurosensory retina that nourishes retinal visual cells, and is firmly attached to the underlying choroid and overlying retinal visual cells.
Riboflavin, also known as vitamin B2, is a vitamin found in food and used as a dietary supplement.
Rickets is a condition that results in weak or soft bones in children.
Rod cells are photoreceptor cells in the retina of the eye that can function in less intense light than the other type of visual photoreceptor, cone cells.
Signal transduction is the process by which a chemical or physical signal is transmitted through a cell as a series of molecular events, most commonly protein phosphorylation catalyzed by protein kinases, which ultimately results in a cellular response.
Skin cancers are cancers that arise from the skin.
Skin whitening is the practice of using substances, mixtures, or physical treatments to lighten skin color.
Sodium/potassium/calcium exchanger 5 (NCKX5), also known as solute carrier family 24 member 5 (SLC24A5), is a protein that in humans is encoded by the SLC24A5 gene that has a major influence on natural skin colour variation.
Smoking cessation (also known as quitting smoking or simply quitting) is the process of discontinuing tobacco smoking.
Solar irradiance is the power per unit area received from the Sun in the form of electromagnetic radiation in the wavelength range of the measuring instrument.
The stratum basale (basal layer, sometimes referred to as stratum germinativum) is the deepest layer of the five layers of the epidermis, the outer covering of skin in mammals.
The upper portion of the spiral ligament (which forms the outer wall of the cochlear duct) contains numerous capillary loops and small blood vessels, and is termed the stria vascularis.
Structural coloration is the production of colour by microscopically structured surfaces fine enough to interfere with visible light, sometimes in combination with pigments.
The substantia nigra (SN) is a basal ganglia structure located in the midbrain that plays an important role in reward and movement.
Sun tanning or simply tanning is the process whereby skin color is darkened or tanned.
Sunburn is a form of radiation burn that affects living tissue, such as skin, that results from an overexposure to ultraviolet (UV) radiation, commonly from the sun.
Switzerland, officially the Swiss Confederation, is a sovereign state in Europe.
Tocopherols (TCP) are a class of organic chemical compounds (more precisely, various methylated phenols), many of which have vitamin E activity.
In chemistry, the term transition metal (or transition element) has three possible meanings.
Tyrosinase is an oxidase that is the rate-limiting enzyme for controlling the production of melanin.
Tyrosine (symbol Tyr or Y) or 4-hydroxyphenylalanine is one of the 20 standard amino acids that are used by cells to synthesize proteins.
Ultraviolet (UV) is electromagnetic radiation with a wavelength from 10 nm to 400 nm, shorter than that of visible light but longer than X-rays.
In cell biology, a vesicle is a small structure within a cell, or extracellular, consisting of fluid enclosed by a lipid bilayer.
Structural proteins linking the viral envelope with the virus core.
Virulence is a pathogen's or microbe's ability to infect or damage a host.
A vitamin is an organic molecule (or related set of molecules) which is an essential micronutrient - that is, a substance which an organism needs in small quantities for the proper functioning of its metabolism - but cannot synthesize it (either at all, or in sufficient quantities), and therefore it must be obtained through the diet.
Vitamin D is a group of fat-soluble secosteroids responsible for increasing intestinal absorption of calcium, magnesium, and phosphate, and multiple other biological effects.
Waardenburg syndrome is a rare genetic disorder most often characterized by varying degrees of deafness, minor defects in structures arising from the neural crest, and pigmentation changes.
The zona reticularis is the innermost layer of the adrenal cortex, lying deep to the zona fasciculata and superficial to the adrenal medulla.
Black melanin, Brown eumelanin, Catechol melanin, Catechol melanins, Eumelanic, Eumelanin, Melanin synthesis, Melanins, Melanization, Melanized, Phaeomelanic, Phaeomelanin, Pheomelanin, Plant melanin.