No valves exist between the anterior vena cava and the heart, and the heartbeat tends to cause movement within this blood vessel. Another vessel, the posterior vena cava, carries blood from the lower half of the body to the heart.
The 2016 Hereford, Texas, population is 15,021. There are 2,447 people per square mile (population density).
Not to be confused with Dallam County, Texas. Dallas County is a county in the U.S. state of Texas. As of the 2010 census, the population was 2,368,139. It is Texas' second-most populous county and the ninth-most populous in the United States. Its county seat is Dallas, which is also Texas' third-largest city and the ninth-largest city in the United States.