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).
It is a northwestern suburb of Dallas. The 2000 United States Census placed the city's population at 77,737 and the 2010 Census placed it at 95,290, making it one of the fastest-growing city populations in the United States and the 33rd most populous in Texas.