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.
The right lung is always larger than the left, due to the positioning of the heart. The apex of the lungs is their cranial point. In most species, the lungs are divided into lobes by the bronchial tree: Left Lung-Cranial and Caudal lobes.Right Lung-Cranial, Caudal, Middle and Accessory lobes. The cranial lobe is further divided by an external fissure.he right lung is always larger than the left, due to the positioning of the heart. The apex of the lungs is their cranial point. In most species, the lungs are divided into lobes by the bronchial tree: Left Lung-Cranial and Caudal lobes.