Interstate 635 (Texas) Interstate 635 (Texas) Interstate 635 (I-635) is a partial loop around Dallas, Texas, in the United States between I-20 in Balch Springs and State Highway 121 (SH 121) at the north entrance of the Dallas-Fort Worth International Airport in Grapevine. It intersects I-35E at exits 27B–C, but does not connect with I-35W. It is known locally as the Lyndon B. Johnson Freeway, or LBJ, named after Lyndon B. Johnson, the former U.S. Senator from Texas, 37th Vice President, and the 36th President of the United States. Where I-635 ends at I-20, I-20 continues the LBJ Freeway name heading west. Because
Referred pain of referred pain, threshold differences for stimulating local and referred pain, and somatosensory sensibility changes in the area of referred pain. Hyperexcitability hypothesizes that referred pain has no central mechanism. However, it does say that there is one central characteristic that predominates. Experiments involving noxious stimuli and recordings from the dorsal horn of animals revealed that referred pain sensations began minutes after muscle stimulation. Pain was felt in a receptive field that was some distance away from the original receptive field. According to hyperexcitability, new receptive fields are created as a result of the opening of latent convergent afferent fibers