Prof. Dr. Matthias Ochs / Institute of Functional and Applied Anatomy / MHH

Research report 2013

The cover image of the 2013 research report shows a three-dimensional reconstruction based on an electron tomographic data set depicting a section of the interior of a type II alveolar epithelial cell of the lung.

The inner surface of the lung is over 100 m2 in size and distributed over around 500 million alveoli. The type II cells are regarded as "defenders" of the alveoli, as they generate cell replenishment and produce a surface-active substance (surface active agent = surfactant) and release it onto the alveolar surface.

Surfactant has biophysical and immunomodulatory properties that ensure that the alveoli are kept open, dry and clean. Inside the type II alveolar epithelial cells, surfactant is stored in specific secretory vesicles called lamellar bodies. Shown here is the connection of a lamellar body with an autophagosome in which the cell's own material is degraded. The detection of such a connection helps to clarify the cellular processes involved in the development of pulmonary fibrosis. It is only a few nanometers wide and can only be visualized in this form using electron tomography. The specimen is tilted in the electron beam, creating a series of projection images that enable a three-dimensional reconstruction and segmentation of relevant structures.

The resulting model can then be rotated and viewed from any direction.

  • Yellow: enveloping membrane of lamellar body and autophagosome.
  • Blue: content of the autophagosome.
  • Brown: content of the lamellar body.


The image was provided by Prof. Dr. Matthias Ochs, Director of the Institute of Functional and Applied Anatomy and Co-Head of the Central Research Facility Electron Microscopy.