In the United States, the carriers have effectively exited the tower business. Most sold their towers to companies like American Tower (AMT) and Crown Castle. These companies construct, maintain and operate the towers, and lease space to the carriers. Tower operators such as AMT actively seek to lease the same tower to multiple carriers, and this is a key metric of their financial success. A best-in-class tower operator will have 2-3 carrier tenants per tower.
The descending aorta is the part of the aorta beginning at the aortic arch that runs down through the chest and abdomen. The descending aorta anatomically consists of two portions or segments, the thoracic and the abdominal aorta, in correspondence with the two great cavities of the trunk in which it is situated.
The only difference between the ascending and descending aorta is the direction of the artery. The ascending aorta is only the area from the aortic semilunar valve to the aortic trunk. The descending is the part of the artery that takes it down the abdomen.The difference in the superior and inferior vena cava is the same, where the superior runs cranially and the inferior runs down the abdomen.They both, vena cavae, dump into the right atrium. :) I hope that answers your question.You have the flow listed correctly already.he only difference between the ascending and descending aorta is the direction of the artery. The ascending aorta is only the area from the aortic semilunar valve to the aortic trunk. The descending is the part of the artery that takes it down the abdomen.