Melanin has many biological functions, including colouring the skin and hairs or feathers, strengthening plant cell walls and insect cuticle, absorbing light (and so providing photoreceptor shieldlng, thermoregulation, photoprotectlon), and it is an important free radical sink.
Medical Definition of autistic disorder. : autism Autistic disorder is classic autism, one of the more severe disorders on the spectrum. Persons with autistic disorder have substantial impairment in social skills, verbal communication, and cognitive and behavioral flexibility.âIsabelle Rapin , The New England Journal of Medicine, 1 Aug. 2002.
Report Abuse. Autistic Spectrum Disorder is a disorder where the person has difficulty processing sensory input in the usual way. They are not retarded or mentally challenged-it's a disorder, not a condition. Those with ASD simply process information in a different way. One person with ASD might find walking barefoot in the grass is pleasurable, another might find it intolerable.