Title: Alveolar cells in the lung
Scheme electron microscopy, human.
(5) alveolar space.
(6) type I Pneumocyte.
(7) basal lamina.
(9) collagen and elastin fibers.
(10) mesothelial cell of the visceral pleura.
(11) capillary with erythrocyte.
(12) endothelial cell lining the capillary.
(13) type II pneumocyte with multilamellar bodies (cytosomes).
(14) alveolar macrophage.
Keywords/Mesh: respiratory tract, lung, Air-Blood barrier, alveolus, type I pneumocyte, alveolar cell type I, type II pneumocyte, alveolar cell type II, alveolar macrophage, interstitial cell, interstitium, collagen fiber, elastin, histology, electron microscopy, POJA collection
a 8.5 POJA-L387
Title: Type II and type I alveolar cells in the lung
Electron microscopy, human. At the top
the alveolar space (1) is lined by a thin cytoplasm (2) of type I alveolar cell (pneumocyte I). At the left side part of a type II alveolar cell (3, pneumocyte II) with electron-dense remnants of two characteristic multilamellar bodies (4) as well as many organelles. Note at (*) junction between these two epithelial cells. Below a capillary with some erythrocytes (5). The arrows (↓) indicate junctions between the endothelial cell processes.
(6) points to an extension of an interstitial cell squeezed between capillary (5) and the pneumocytes (2,3). Thin-walled areas (not shown here) are most favourable to gas exchange and alternate with a thicker-walled area (thick line, ▬) consisting of extracellular matrix (ECM) and cell process of the alveolar framework that separate the alveolar epithelium from the capillary.
Title: Type I alveolar cell in the lung
Electron microscopy, human. Part of a thick-walled area consisting of supporting fibers, extracellular matrix (ECM) that separate the alveolar epithelium from the capillaries.
At the top the alveolar space is lined by type I alveolar cell (1, pneumocyte I). The cytoplasm is well provided with organelles and few electron-dense lysosomes, and pinocytotic vesicles. These pneumocyte I cells cover the interalveolar septa that contain fibroblasts and bundles of thin collagen fibers (3) and darker-stained elastin fibers(4). At (2) the basal membranes of the alveolar epithelial cells.