
Parts and Bonds
Ashley Davidoff MD

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 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)
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Ashley Davidoff MD
TheCommonVein.net

The diagram shows an alveolus, lined by a single layer of squamous cells,
Ashley Davidoff MD TheCommonVein.net lungs-0705-lo res

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
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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

Ashley Davidoff TheCommonVein.net 42438b03

key words
key words RS lung alveolus respiratory bronchiole artery vein pulmonary capillary normal anatomy histology drawing
Ashley Davidoff MD TheCommonVein.net 32164

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
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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 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

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Ashley Davidoff MD
TheCommon Vein.net

Ashley Davidoff MD TheCommonvein.net lungs-0056

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
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Ashley Davidoff MD TheCommonVein.net lungs-0057
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Inflamed AlveoliAshley Davidoff MD TheCommonvein.net

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

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

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

A hyaline membrane evolves covering the damaged surface of the alveolus. This impedes gas exchange
Ashley Davidoff
TheCommonVein.net