Why do we call it a funny bone?

The funny bone is a spot on the elbow that is painful when hit. If there's anything funny about it, it's that the funny bone isn't a bone at all. It's actually a semi-exposed nerve called the ulnar nerve that runs around the elbow. The ulnar nerve controls feeling in the fourth and fifth fingers and is one of the nerves that controls movement of the wrist.

One theory about the name is that it derived as a pun on the Latin word humerus, which describes the part of the arm between the shoulder and the elbow.

Another theory is the name derived from the strange tingling sensation that occurs when the ulnar nerve bumps against the humerus. So, funny as in strange rather than funny as in humor.

But the funny bone has some humorous connotations. If something strikes you as funny, you might say it "tickled your funny bone." Nevertheless: one thing is for certain: hitting your funny bone won't make you laugh.

Resources:

A little more about the funny bone from Life Science Connections.