Anatomy and method The pharynx The performer must first lean the head back, hyper-extending the neck, and relax the upper esophageal sphincter (a generally involuntary muscle that contracts the top of the esophagus). Retching must be controlled while the sword, lubricated by saliva, is inserted through the mouth and past the pharynx. Once past the pharynx and sphincter the sword passes swiftly, assisted by gravity, straightening the flexible esophagus. The stomach, at an angle to the esophagus, is brought into line as the sword enters through the cardiac opening. Some swallowers consume a large meal or drink water before performing to give the stomach a more vertical orientation, allowing for easier passage of the sword.Careful focus is required to complete the process without injury, as the sword passes within millimetres of vital body parts such as the aorta, heart and lungs. Source
