Do you only need to worry about the Breathing, Bleeding, and Brain?

I mean in a nut shell, really I've been studding med. stuff for a wile and it seems to be true. Only need to worry about 3 things. The lungs, breathing etc., the heart, bleeding, etc.., and The brain, nerves etc..





'What do you think about this statement?' It was told to me by a EMT this one time.

Do you only need to worry about the Breathing, Bleeding, and Brain?
Reminds me of two old sayings in the EMS community, "air goes in and out, blood goes 'round and 'round...any variation on this is a bad thing" and "all bleeding stops eventually" :D