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).
Texas is the second most populous U.S. state, with an estimated 2017 population of 28.449 million. In recent decades, it has experienced strong population growth. Texas has many major cities and metropolitan areas, along with many towns and rural areas. Much of the population is in the major cities of Houston, San Antonio, Dallas, Fort Worth, Austin, and El Paso.