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.
Autism spectrum disorder is a serious neurodevelopmental disorder that impairs a child's ability to communicate and interact with others.It also includes restricted repetitive behaviors, interests and activities. These issues cause significant impairment in social, occupational and other areas of functioning.lthough the term Asperger's syndrome is no longer in the DSM, some people still use the term, which is generally thought to be at the mild end of autism spectrum disorder. The number of children diagnosed with autism spectrum disorder is rising.