Department is related to Specific. Specific is a type of Medicine. you are likely to find Medicine in/at/on Doctor. you are likely to find Scale in/at/on Doctor. 
you are likely to find Hair in/at/on Food. Lock is a type of Hair. Lock is related to Bolt. 
Department <--RelatedTo--> Specific --IsA--> Medicine --AtLocation--> Doctor <--AtLocation-- Scale 
Food <--AtLocation-- Hair <--IsA-- Lock <--RelatedTo--> Bolt 