A complete, schematic view of the human respiratory system with their parts and functions. File:Anatomy of the respiratory system. The anatomy and physiology that make this happen varies greatly, depending on the size of the organism, the environment in which it anatomy of the respiratory system pdf and its evolutionary history.
These microscopic air sacs have a very rich blood supply, thus bringing the air into close contact with the blood. This water flows over the gills by a variety of active or passive means. The intervals between successive branch points along the various branches of “tree” are often referred to as branching “generations”, of which there are, in the adult human about 23. 4th order, 5th order, and 6th order segmental bronchi, or grouped together as subsegmental bronchi. The alveoli are the dead end terminals of the “tree”, meaning that any air that enters them has to exit via the same route. At the end of inhalation the airways are filled with environmental air, which is exhaled without coming in contact with the gas exchanger.
The lungs expand and contract during the breathing cycle, drawing air in and out of the lungs. Not all the air in the lungs can be expelled during maximally forced exhalation. 5 liters which cannot be measured by spirometry. Their measurement requires special techniques. The rates at which air is breathed in or out, either through the mouth or nose, or into or out of the alveoli are tabulated below, together with how they are calculated.