creatinine is a normal waste product produced by muscle metabolism when your kidneys are functioning normally they filter creatinine and other waste products out of your blood and send them out of the body through urine
Tweet. This follows the page describing the basic anatomy of the lower respiratory tract. The term  tracheobronchial tree  or  respiratory tree  refers to the structures of bronchi and bronchioles that terminate with the alveolar ducts, sacs, and, finally, alveoli-that are contained within the lungs.herefore these structures are also referred to as  airways . This pages includes two diagrams of the airways-the main structure of the tracheobroncial tree being shown immediately below, and a second diagram showing the alveoli in further detail further down the page.
Pneumothorax. A pneumothorax is a rupture of the air sacs, or alveoli, in the lung. As the baby breathes air into the lungs, some of that air goes through the rupture and into what is called the pleural space or cavity that surrounds the lung.The air that enters this cavity puts pressure on the lung from the outside, squeezing and squashing the underlying lung, making breathing more difficult.s the baby breathes air into the lungs, some of that air goes through the rupture and into what is called the pleural space or cavity that surrounds the lung. The air that enters this cavity puts pressure on the lung from the outside, squeezing and squashing the underlying lung, making breathing more difficult.