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 itch the arcuate nucleus, this explains why the face remains unaffected by referred itch. Some spread in association within the cerebral cortex may also explain the large distances between trigger points and referred sensation sites. In the precentral area where the homunculus rests, it is known that hand and shoulder areas overlap the trunk area. And the area of the thumb overlaps that of the upper part of the tongue. There is a published case in which stimulation in the thumb led to a referred sensation in the upper part of the tongue. The origin of referred itch is unknown, whether