Fats, such as the fats in milk, need to be digested by your body. They are broken down into fatty acids and glycerol by an enzyme called lipase. Gastric lipase, secreted by the stomach lining, has a pH value for optimal activity around neutrality and would appear, therefore, to be essentially inactive in the strongly acid environment of the stomach.
The structures of your upper respiratory system are always working overtimeâfiltering air, expelling pollutants, and relying on other anatomy to remain healthy and intact. Let's take a look at some of the structures and jobs of the upper respiratory system. Nasal Cavity The nasal cavity is a chamber of the internal nose that connects to the nasopharynx. Air is inhaled through the nostrils and warmed as it passes through the nasal cavities.
airway. 1  an air route equipped with emergency landing fields, beacon lights, radio beams, etc. 2  a passageway by which air passes from the nose or mouth to the air sacs of the lungs. 3  Medicine/Medical. a tubelike device used to maintain adequate, unobstructed respiration, as during general anesthesia.