Have you ever hit your elbow and felt that sudden jolt of discomfort? Or maybe you’ve experienced that strange tingling sensation when your hand falls asleep? Well, you can thank the ulnar nerve for both of these experiences. As one of the three major nerves that travel from the neck down to the hand, wrist, and fingers, the ulnar nerve plays a significant role in our daily lives. Interestingly, it gets its name from its close relationship with the ulna bone located in the forearm.
Anatomy of the Ulnar Nerve
The ulnar nerve is a part of the brachial plexus, which is a larger network of nerves. It originates from the brachial plexus and travels down the shoulder, extending into the arm. As it makes its way, the ulnar nerve passes through the cubital tunnel, which is a hollow tunnel of tissue located on the inner side of the elbow. This tunnel is positioned behind and beneath the medial epicondyle of the humerus, which is more commonly known as the “funny bone.”
Three Functional Branches
The ulnar nerve is responsible for carrying signals from the shoulder to the elbow joint. It runs through the muscles along the ulna bone in the forearm. Once it reaches the elbow, the nerve splits into three branches, each serving a different function.
The first branch is known as the arterial branch, which spans from the shoulder to the elbow joint. This branch is responsible for providing the nerve with the necessary blood supply.
At the elbow, the ulnar nerve further divides into two additional branches. The first is the muscular branch, which stimulates two muscles located in the inner forearm.
The second branch, known as the palmar cutaneous branch, carries signals to and from the palm of the hand. This branch enables sensory and motor functions in the palm.
The final branch is the dorsal cutaneous branch, which controls movement in the pinky finger and half of the ring finger. This branch allows for fine motor control and sensation in these specific areas of the hand.