Pigments

From Psychology Wiki

Community portal · Tasks to do · News · Help

Clinical · Educational · Ind&Org · Other fields · Professional · Transpersonal · World

Assessment | Biopsychology | Comparative | Cognitive | Developmental | Language
Personality | Philosophy | Research Methods | Social | Statistics

Biological: Behavioural genetics · Evolutionary psychology · Neuroanatomy · Neurochemistry · Neuroendocrinology · Psychoneuroimmunology · Physiological Psychology · Psychopharmacology

The Blue Morpho butterfly, native to Central America, derives its distinctive blue coloring from iridescence rather than from pigmentation.

Biological pigments, also known simply as pigments or biochromes^{[citation needed]} are substances produced by living organisms that have a color resulting from selective color absorption. Biological pigments include plant pigments and flower pigments. Many biological structures, such as skin, eyes, fur and hair contain pigments such as melanin in specialized cells called chromatophores.

Pigment color differs from structural color in that it is the same for all viewing angles, whereas structural color is the result of selective reflection or iridescence, usually because of multilayer structures. For example, butterfly wings typically contain structural color, although many butterflies have cells that contain pigment as well.

[edit] Biological pigments

• Heme/porphyrin-based: bilirubin, hemocyanin, hemoglobin, myoglobin
• Light-emitting: luciferin
• Carotenoids:
  • Carotenes: alpha and beta carotene, anthocyanin, lycopene, rhodopsin
  • Xanthophylls: canthaxanthin, zeaxanthin, lutein
• Proteinaceous: phytochrome, phycobiliproteins
• Polyene enolates: a class of red pigments unique to parrots
• Other: melanin, urochrome,

[edit] Pigments in animals

The monarch butterfly's distinctive pigmentation reminds potential predators that it is poisonous.

Pigments in animals may serve to protect tissues from ultraviolet radiation, such as melanin in the skin. Pigments may also aid in sexual reproduction, identifying species and gender of animals to potential mates, or signalling readiness to breed.

Some cephalopods use pigmented chromatophores to communicate.

Pigmentation is used by many animals for protection, by means of camouflage, mimicry, or warning coloration. Chameleons use pigments to blend into their surroundings by controlling the absorption levels of the electromagnetic spectrum.

[edit] Diseases and conditions

A variety of diseases and abnormal conditions that involve pigmentation arise in humans and animals, either from absence of or loss of pigmentation or pigment cells, or from the excess production of pigment.

• Albinism is an inherited disorder characterized by total or partial loss of melanin. Humans and animals that suffer from albinism are called "albinistic" (the term "albino" is also sometimes used, but may be considered offensive when applied to people).
• Lamellar ichthyosis, also called "fish scale disease", is an inherited condition in which one symptom is excess production of melanin. The skin is darker than normal, and is characterized by darkened, scaly, dry patches.
• Melasma is a condition in which dark brown patches of pigment appear on the face, influenced by hormonal changes. When it occurs during a pregnancy, this condition is called the mask of pregnancy.
• ocular pigmentation is an accumulation of pigment in the eye, and may be caused by latanoprost medication.^[1]
• Vitiligo is a condition in which there is a loss of pigment-producing cells called melanocytes in patches of skin.

[edit] =See also

• Animal coloration
• Eye color

[edit] References

This page uses content from the English-language version of Wikipedia. The original article was at Biological pigment. The list of authors can be seen in the page history. As with Psychology Wiki, the text of Wikipedia is available under the GNU Free Documentation License.