This document discusses functional disorders of the salivary glands, including sialorrhea/ptyhalism and xerostomia. Sialorrhea is characterized by increased salivary secretion that can be caused by systemic factors like paralysis or psychological factors. Xerostomia refers to a decreased amount of saliva and can be caused pharmacologically by drugs like antihistamines or systemically by conditions like diabetes that result in fluid loss. Both conditions present clinical features like drooling of saliva or fissuring of the tongue. Management may include drugs to stimulate saliva production, salivary substitutes, or surgery in severe cases.