Uncategorized

 

Alveolus
Parts and Bonds
Ashley Davidoff MD
Lungs and The Common Vein
The image shows some of the major components of the lung that when bonded create a new and powerful unit – a vital organ. In the center is an example of the airways and parenchyma making up the 2 lungs. At 12 oclock the tracheo-bronchial tree with segmental and subsegmental airways. At 1 o?cloclock, is a cross section of the lungs showing some of the segments of the lung. At 5o?clock a cross section shows the arteries and veins of the lungs. At 7o?clock the drawing shows the pleura and pleural space of the lungs. At 9o?clock, a coronal reformat of the tracheobronchial tree shows the lymph node stations of the lungs. At 11 o?clock is the golden alveolus, the epicentral unit where gas exchange takes place
Ashley Davidoff MD TheCommonVein.net lungs-0696-lo res
The Alveolus – The Centre of the Pulmonary Universe
The five major layers that keep the air moving include the outer bony cage, the muscular layer represented in maroon, the pleural complex (orange yellow orange) the lung (blue) and surfactant within the alveolus. (pink)
 42530b05b09b01a08
Ashley Davidoff MD
TheCommonVein.net
The Squamous Epithelium of the Alveolus
The diagram shows an alveolus, lined by a single layer of squamous cells,
Ashley Davidoff MD TheCommonVein.net lungs-0705-lo res

 

The Alveolus 3D
This drawing demonstrates the open mouth view of the alveolus, which is surrounded by its capillary network. The lining single layer of squamous cells (pneumocytes) can be seen peaking through the vessels.
Ashley Davidoff MD.
TheCommonVein.net
32166
The Alveolus 3D
This drawing demonstrates the open mouth view of the alveolus, which is surrounded by its tree like capillary network. The lining single layer of squamous cells (pneumocytes) can be seen peaking through the vessels.
Ashley Davidoff MD. TheCommonVein.net lungs-0022
The Alveolus                                                                                                                                                                           In this diagram a single alveolus is outlined with its surrounding arteriole, venule, and capillary network.  The process at the alveolar end is a simple exchange. Life sustaining oxygen is received by the hemoglobin and toxic carbon dioxide is excreted.  Although this exchange occurs in the respiratory bronchioles alveolar ducts and alveolar sacs, the alveolus is the prime site of gaseous exchange.
Ashley Davidoff TheCommonVein.net 42438b03
This is a drawing of a cluster of alveoli surrounded by the capillary network, fed by an arteriole in blue, and drained by a venule in red.
key words
key words RS lung alveolus respiratory bronchiole artery vein pulmonary capillary normal anatomy histology drawing
Ashley Davidoff MD TheCommonVein.net 32164
Alveolus at a Cytologic Level
The diagram shows an alveolus (a) above, lined by a single layer of squamous cells, surrounded by a capillary with red cells which is also lined by a single layer of squamous endothelial cells . The images below show progressive magnification of the alveolar wall demonstrating the two thin layer of the alveolar membrane .
Courtesy Ashley Davidoff 2019
lungs-0028-low res
Exchange of Gases Across the Alveolar Membrane
The diagram shows an alveolus, lined by a single layer of squamous cells, surrounded by a capillary with red cells which is also lined by a single layer of squamous endothelial cells . The images show exchanges of oxygen and carbon dioxide through the alveolar membrane .
Ashley Davidoff MD TheCommonVein.net lungs-0028b-low res
The Alveolus –
The Buck Ends Here
The alveolus is lined by a simple epithelium ? one cell layer thick. There are two types of lining cells; Type 1 pneumocytes are squamous cells that cover 90% of the surface of the inner lining of the lung , and type II cuboidal pneumocytes that are in fact much more numerous than Type I. They are involved in the production of surfactant . In the lumen there are resident macrophages which play a crucial role in the immune system. The mucosa is grounded by a basement membrane and a lamina propria, and connected to the lamina propria and basement membrane of the surrounding capillary. The alveolus is lined by a thin layer of surfactant. (teal blue)
Ashley Davidoff
TheCommonVein.net
Alveoli in an Acinus of a Secondary Lobule
lungs-0008
Ashley Davidoff MD
TheCommon Vein.net
Alveolus as a Part of the Acinus
Ashley Davidoff MD TheCommonvein.net lungs-0056
Alveoli of the Lung ? Factory Workers
This is a drawing of a cluster of alveoli surrounded by the capillary network, fed by an arteriole in blue, and drained by a venule in red. The second image shows the exchange of life giving oxygen for the by product of  metabolic activity ? carbon dioxide
Ashley Davidoff MD
TheCommonVein.net
32165c
The Devil is in the Chest and Lungs and has One Mission
Ashley Davidoff MD TheCommonVein.net lungs-0057

lungs-0021catalogue-signed-smallb.jpg

 Inflamed Alveoli
Ashley Davidoff MD TheCommonvein.net
Early Events in the Pathophysiology of the ARDS
The initial injury results in an acute severe inflammatory response consisting hyperemia , edema with migration initially of neutrophils in the first 6-24 hours followed by monocytes (24-48hours). The intra -alveolar macrophages are activated.
Ashley Davidoff
TheCommonVein.net
Result of Cellular Response
The cells of the immune system release cytokines, chemotactic agents and proteases. Immune cells , macrophages and fibroblasts are attracted to the interstitium. Some of proinflammatory agents are toxic to the cell lining causing damage to the surfactant, type 1 pneumocytes and the capillary endothelium. There is progressive edema.
Ashley Davidoff
TheCommonVein.net
Result of Cellular Response and Associated Tissue Injury
The damage to the endothelium of the capillary results in bleeding into the alveoli. The severe tissue damage and fluid exudation results in protein rich intra-alveolar fluid . The fibroblasts start to lay down collagen as part of the early repair process
Ashley Davidoff
TheCommonVein.net
Hyaline Membrane
A hyaline membrane evolves covering the damaged surface of the alveolus. This impedes gas exchange
Ashley Davidoff
TheCommonVein.net

Links and References