From the vena cava (superior and inferior), the blood enters the heart (right atrium), is pumped into the right ventricle, and then pumped into the lungs (through the Pulmonary Arteries), where carbon dioxide is exchanged for oxygen.
Harlan, Iowa. Harlan is a city in Shelby County, Iowa, United States, along the West Nishnabotna River. The population was 5,106 at the 2010 census. It is the county seat of Shelby County.
Johnson County is the second-fastest-growing county in Iowa, according to U.S. Census Bureau estimates released Thursday. The census data estimate that from 2010 to 2015, Johnson County's population grew by 10.2 percent, or 13,369 residents, bringing the estimated county population to 144,251.