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).
Midland is a city in and the county seat of Midland County, Texas, United States, on the Southern Plains of the state's western area. A small portion of the city extends into Martin County. At the 2010 census, the population of Midland was 111,147, and a 2015 estimate of 132,950, making it the twenty-fourth most populous city in the state of Texas. Due to the oil boom in Midland, certain officials have given population estimates above 155,000. It is the principal city of the Midland, Texas Metropolitan Statistical Area, which includes all of Midland County.