P. Carinii Cysts
Description: In efficient gas exchange, oxygen and carbon dioxide must cross five barriers: red blood cells, capillary membrane, interstitial fluid, alveolar membrane and surfactant. P. Carinii cysts harboring in the alveolar sacs and interstitial spaces add another barrier. Shows cysts, red blood cells, capillaries, type 1 and 2 cells and alveoli.