What Is the Function of the Phrenic Nerve?

The phrenic nerve controls the diaphragm, a muscle located under the lungs. The phrenic nerve signals the diaphragm muscle to contract when a person is about to inhale. When the diaphragm muscle contracts, it moves downward, leaving room for the lungs to expand. This allows air to travel through the nose and mouth before entering the windpipe.

Phrenic nerve damage results in difficulty breathing and increases the risk for lung infections. In some cases, the phrenic nerve is injured during surgery on the neck or chest. Lung surgery, heart valve surgery, coronary bypass surgery and surgery to treat cancers of the head and neck have all been linked to phrenic nerve injuries. This nerve is also susceptible to injuries sustained during auto accidents and falls, epidural injections and manipulation of the neck during chiropractic treatment.

If someone is unable to breathe independently due to phrenic nerve damage, a phrenic nerve pacer is used to make the diaphragm muscle contract. The phrenic nerve pacer has several advantages over a traditional ventilator because it is an implantable device. Someone with the device can speak normally, and there is no tube in the mouth to prevent the person from eating or drinking. It may also be possible for the injured person to undergo a nerve transplant or nerve decompression procedure.