Usually applied to the projection, the olecranon
, at the back of the elbow, which is the upper end of the ulna
, one of the two forearm bones. On the inner side of this is a smaller protuberance, the medial epicondyle
of the humerus
— the bone of the upper arm. The ulnar nerve
runs in a groove on the back of the epicondyle, between this and the olecranon. The nerve can be felt and rolled under the fingers, most easily when the elbow is at a right angle, and because it is near the surface it can be painfully tweaked if the inner side of the elbow hits a hard surface. The sensation is funny only in the sense of peculiar. (Tempting though it be, there is apparently no pun intended to link it to the humerus — whose name is Latin for shoulder, referring to its upper end.)
the part of the elbow over which the ulnar nerve passes. A knock on the funny bone may cause numbness and pain along the forearm and hand.
a person's sense of humor, as located in an imaginary physical organ:
photographs to jostle the mind and the funny bone.