Where did the crazy injuries of anime come from?

[Warmmedown]

How did the trend of anime charas losing an arm but still fighting, or getting other crazy injuries but being able to fight begin? Does this predate anime? Was it a case of more realistic stories of fighting with injuries initially, such as losing an arm, giving it first aid for a while and then fighting on, but once that became accepted it got turned into a truncated version of almost immediately fighting after losing an arm, which just represented the original story and left out some of the realism?

When did coughing up blood in fights become a thing?

 

[Scott]

Dunno. Maybe Shirato Sampei popularized it; his manga was pretty bloody.