Department is related to Bureau. you are likely to find Bureau in/at/on Bedroom. 
Impulse is etymologically related to Pulse. Impulse is related to Spark. Spark is related to Tiny. Tiny is related to Cell. 
Department <--RelatedTo--> Bureau --AtLocation--> Bedroom 
Pulse <--EtymologicallyRelatedTo-- Impulse <--RelatedTo--> Spark <--RelatedTo--> Tiny <--RelatedTo--> Cell 