Fig 7.

Diagram of a pancreatic acinar cell illustrating subcellular landmarks and ultrastructural criteria used for morphometric analysis. The progranule zone (- - -) is limited by the outermost of the Golgi cisternae, the MG and the rough endoplasmic reticulum. Note that some profiles classified by these criteria as products of fused PG can appear identical in ultrastructure to some profiles classified as ‘immature granules’ (IGs) because the distinction is based on whether the structure is in the progranule zone (the unit progranules and products of fused progranules) or outside this zone (the immature granules). The numbers associated with unit PG₁, structures interpreted as products of fused PG_2–100, or MG1–10 indicate the sizes of the structures in equivalent granule unit volumes, with all of these structures illustrated as if the plane of section was through the equator of the structures. Thus, a MG₂ would have a volume twice that of an MG₁. (Reproduced from [17], with the permission of the publisher.)