, Physiologist. 1  In four chambered avian and mammalian hearts, the two upper chambers are known as the atria. The atria are believed to act as primer pumps which boost the end diastolic volume (the volume at the end of ventricular filling) just before contraction of the ventricles.
Disunion follows the Civil War as it unfolded. New Orleans was the jewel of the Confederacy. In addition to being the Southâs largest city, it boasted considerable industry that produced ironclads, munitions and uniforms, among other items. More important, it controlled access to the Mississippi River from the Gulf of Mexico.
Earlier, in 1803, Louisiana had become a part of the United States because of the region's importance to the trade and security of the American mid-west. New Orleans and the surrounding territory controlled the mouth of the Mississippi River down which much of the produce of the mid-west travelled to reach market.