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 trachea, commonly known as the windpipe, is a tube about 4 inches long and less than an inch in diameter in most people. The trachea begins just under the larynx (voice box) and runs down behind the breastbone (sternum).The trachea then divides into two smaller tubes called bronchi: one bronchus for each lung. Tracheal foreign body: An object is inhaled (aspirated) and lodges in the trachea or one of its branches. 2  A procedure called bronchoscopy is usually needed to remove a foreign body from the trachea. 3  Tracheal cancer: Cancer of the trachea is quite rare. 4  Symptoms can include coughing or difficulty breathing.