In computer networks and telecommunications, a dedicated line is a communications connection or other hardware resource dedicated to a certain application or use. This is different than a shared connection such as a telephone network or the Internet.
Carbon dioxide, a waste product of metabolism, travels from the blood to the alveoli, where it can be exhaled. Between the alveoli is a thin layer of cells called the interstitium, which contains blood vessels and cells that help support the alveoli. The lungs are covered by a thin tissue layer called the pleura. The same kind of thin tissue lines the inside of the chest cavity -- also called pleura. A thin layer of fluid acts as a lubricant allowing the lungs to slip smoothly as they expand and contract with each breath.
The lungs are the body's major organs of respiration. The two vital parts that make up the lungs are located on each side of the chest within the rib cage. They are separated by the heart and other contents of the mediastinumthe tissues and organs of the middle chest (e.g., the heart and large vessels, windpipe).xygen-poor blood is brought back to the lungs by the pulmonary artery. The pulmonary artery divides into branches that parallel the bronchial tubes and ends in a network of pulmonary capillaries (tiny blood vessels) within the walls of the small air passages and alveoli of the lungs.