This response is known as striking the "funny bone". The name funny bone could be from a play on the words humorous and humerus, the bone on which the medial epicondyle is located, although according to the Oxford English Dictionary, it may refer to "the peculiar sensation experienced when it is struck".
This response is known as hitting the "joke point". The term "joke point" could be derived from a wordplay involving humor and the bone, the humerus, where the medial epicondyle is situated. According to the Oxford English Dictionary, it may refer to "the peculiar sensation experienced when struck."