I think of it like I think of electronics, or plumbing... Let's say you have a nice circuit, and at every point in the circuit, there is a measurable voltage (amount of oxygen available) and everything hums along. Now, suddenly, one of the resistors burns out, going open-circuit. Sure, electrons are still flowing everywhere else. Maybe no other parts fail in a sudden chain-reaction. But you definitely are hearing a lot of distortion that wasn't there a minute ago. Or maybe only one channel works, and the other one makes no sound at all.
In the human body, there are critical paths for blood where no redundancy exists. It all goes through the heart. I only have one of those. As far as I know, none of my collateral veins has a valve in it. Congenital malformations are not congenital reformations. They do not enhance us.
"Try - Just A Little Bit Harder" - Janis Joplin
CCSVI procedure Albany Aug 2010
'MS' is over - if you want it
Patients sans/without patience