Functionally, these neurons are either motor (conducting impulses that will cause activity such as the contraction of muscles) or association (conducting impulses and permitting 'communication' between neurons within the central nervous system).
The scant research that has been done on the causes of pica suggests that the disorder is a specific appetite caused by mineral deficiency in many cases, such as iron deficiency, which sometimes is a result of celiac disease or hookworm infection.
Practice Essentials. Pica is an eating disorder typically defined as the persistent ingestion of nonnutritive substances for at least 1 month at an age for which this behavior is developmentally inappropriate. It may be benign or may have life-threatening consequences.