Figure 4 - Effect of transection of various motor nerves on the motor responses of the UES closing muscles during swallowing.

Each panel of this figure depicts the electromyography (EMG) responses of the muscles of the UES during swallowing activated by injection of 1 mL of water into the pharynx of a decerebrate cat. The headings of each panel indicate the nerves that were transected before the stimulus. Note that transection of the superior laryngeal nerve (SLN) and recurrent laryngeal nerve (RLN) bilaterally had no significant effect on the EMG responses of all muscles, but that the additional transection of the pharyngoesophageal nerve (PEN) bilaterally blocked responses of the cricopharyngeus (CP) and esophagus (ESO) 1 cm below CP, but had no significant effect on the thyrohyoideus (TH) or thyropharyngeus (TP).