Question

if you touch at elbow, you get a shock like feeling. Why

Answer 1

The ulnar nerve is one of the three main nerves in your arm. It travels from your neck down into your hand. At the elbow, the ulnar nerve travels through a tunnel of tissue that runs under a bump of bone at the inside of your elbow. This bony bump is called the medial epicondyle. The spot where the nerve runs under the medial epicondyle is commonly referred to as the "funny bone." At the funny bone the nerve is close to your skin, and bumping it causes a shock-like feeling.

Answer 2

in human beings ulnar nerve runs from the shoulder to the hand
the ulnar nerve comes close to the surface near to the elbow
due to the superficial location it is not protected by the muscle or any tissue
thinner skin layer at elbow makes ulnar nerve more receptive for any small stimuli
that's the reason for getting shock like feeling