Eli5 Why does hitting your funny bone hurt so dang bad?



Eli5 Why does hitting your funny bone hurt so dang bad?

In: Biology

Funny bone is actually a nerve so when you bang it up, you squish the nerve against the bone and that’s what makes you feel so awful

Because the ulnar nerve runs on the underside of the point of your elbow and is basically unprotected. It is the largest unprotected nerve in the human body and is responsible for the feeling in your pinky and half of your ring ringer. When you “hit your funny bone” you’re actually impacting this nerve.

Right above the elbow right? Not a lot of cushion (fat or muscle), so the nerve is more exposed to the blunt force. Nerves are sensitive to and are what help detect things like pressure and temperature hence why it’s so painful.

This is my observation though experience and what I think is going on. An MD could probably give a more precise and correct reason.

When I was a kid I’d prod around the funny bone area and was able to poke the nerve and it would make my whole arm tingle for a couple seconds (didnt hurt).

Your ulnar nerve runs exposed between the bony processes of your elbow. When you bang your elbow in that exact spot you hit the nerve. This causes the nerve to “fire” in both directions. This is not what the nerve normally does and the signals it produces confuse the brain. You feel this as bizarre tingling etc.