Question

Neck injuries can sever the nerves that control contraction of the diaphragm. How would this affect breathing?

Answer 1

breathing in would be impossible as it requires the diaphragm to contract and move down and flatten to decrease the pressure in the lungs causing air to rush in. 

Answer 2

it would affect breathing by your brain not being able to get signals sent to the diaphragm to pump air into the lungs thus making you have a very difficult time breathing which could cause you to suffocate if not attended to quickly.