Art of Physiology This diagram reflects the laminar flow showing the almost parallel lines of flow that is characteristic of flow in the smaller tubes. Under resting conditions, laminar flow exists from the medium-sized bronchi onward down to the bronchioles. During exercise, the air flow is accelerated, and laminar flow may be confined only to the very small airways.Ashley Davidoff MD TheCommonVein.net lungs-0703 This drawing shows the lines and circles of noisy turbulent flow, which is characteristic of flow in the larger airways.Ashley Davidoff MD TheCommonVein.net lungs-0704 The diagram illustrates the interface of the capillary with an epithelium and the interstitium. The arteriole pressure at the inflow is about 30-40mmHg and drops to a capillary pressure of about 25mmHg The intravascular oncotic pressure is about 28mmHg and the venous out flow pressure is about 10-15mmHg.The fluid thus will move from the capillaries into the interstitiumAshley Davidoff MD The CommonVein.net 42445b03d06 Alveolus at a Cytologic LevelThe 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 .Ashley Davidoff MD TheCommonVein.net lungs-0028-low res Alveolus at a Cytologic LevelThe 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 .Ashley Davidoff MD TheCommonVein.net lungs-0028-low res Exchange of Gases Across the Alveolar MembraneThe 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 Maps of Art and Culture Lungs