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).
Montgomery County is a county in the U.S. state of Texas. As of the 2010 census, its population was 455,746. A 2013 estimate places the population at 499,137. The county seat is Conroe. The county was created by an act of the Congress of the Republic of Texas on December 14, 1837 and is named for the town of Montgomery. Between 2000 and 2010, its population grew by 55%, the 24th-fastest rate of growth of any county in the United States.