Basic is a type of Commodity. Basic is related to Structure. Zone is a type of Structure. Zone is related to Tank. 
Clinical is similar to Objective. Objective is related to Care. Care is related to Medical. Medical is related to Shock. 
Commodity <--IsA-- Basic <--RelatedTo--> Structure <--IsA-- Zone <--RelatedTo--> Tank 
Clinical <--SimilarTo--> Objective <--RelatedTo--> Care <--RelatedTo--> Medical <--RelatedTo--> Shock 