Search results
Results From The WOW.Com Content Network
The ducts number between two and eleven from each bronchiole. [10] Each duct opens into five or six alveolar sacs into which clusters of alveoli open. Each terminal respiratory unit is called an acinus and consists of the respiratory bronchioles, alveolar ducts, alveolar sacs, and alveoli. New alveoli continue to form until the age of eight years.
alveolar duct. alveolar sac. alveolus; At each division point or generation, one airway branches into two smaller airways. The human respiratory tree may consist on average of 23 generations, while the respiratory tree of the mouse has up to 13 generations. Proximal divisions (those closest to the top of the tree, such as the bronchi) mainly ...
Fig. 15 The arrangement of the air sacs and lungs in birds Fig. 16 The anatomy of bird's respiratory system, showing the relationships of the trachea, primary and intra-pulmonary bronchi, the dorso- and ventro-bronchi, with the parabronchi running between the two. The posterior and anterior air sacs are also indicated, but not to scale.
Terminal bronchioles in turn divide into smaller respiratory bronchioles which divide into alveolar ducts. Terminal bronchioles mark the end of the conducting division of air flow in the respiratory system while respiratory bronchioles are the beginning of the respiratory division where gas exchange takes place.
The end of the terminal bronchioles in the lungs mark the beginning of a pulmonary acinus that includes the respiratory bronchioles, alveolar ducts, alveolar sacs, and alveoli. [ 4 ] See also
Thus, it includes the alveolar ducts, sacs, and alveoli but not the respiratory bronchioles. [30] The unit described as the secondary pulmonary lobule is the lobule most referred to as the pulmonary lobule or respiratory lobule. [25]: 489 [31] This lobule is a discrete unit that is the smallest component of the lung that can be seen without aid ...
Within the lungs, the ventilation process specifically involves organs like respiratory bronchioles, alveolar ducts, alveolar sacs, and alveoli. For the perfusion process, the circulatory organs of the cardiovascular system such as the heart, pulmonary arteries, pulmonary veins, and alveolar capillaries are involved.
Alveolar glands, also called saccular glands, are glands with a saclike secretory portion, in contrast with tubular glands. They typically have an enlarged lumen (cavity), hence the name: they have a shape similar to alveoli , the very small air sacs in the lungs.