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.
Located in West Central Iowa, Harlan is the seat of Shelby County government and a short drive on Interstate 80 from Omaha, NE and Des Moines, IA. Harlan is the Shelby County Seat Shelby County's rural tranquility is scattered with timber-bordered, green rolling pastures dotted with sparkling ponds, grazing livestock and fields of corn and soybeans.