Zelllagen

Zelllagen is a term used in histology to describe the arrangement of cells into discrete layers within a tissue. The concept focuses on how cells are organized along a boundary or surface, rather than on the identity of the individual cells. In animal tissues, Zelllagen are most commonly discussed in epithelia, where cells align into layers that provide protection, absorption, or secretion.

The simplest form is a simple layer (einlagige Zelllage), consisting of a single cell tier. More commonly, tissues exhibit stratified layers (mehrlagige Zelllage), which offer greater durability against wear. A subset of epithelia is pseudostratified, where all cells contact the base but nuclei lie at varying depths, giving the appearance of multiple layers without separate cell strata.

In plants, Zelllagen can refer to the layered arrangement of cells within tissues such as the epidermis or cortex, where the organization influences functions like gas exchange, transport, and mechanical properties. The thickness and composition of Zelllagen are shaped by development, mechanical forces, and environmental conditions.

Researchers study Zelllagen using light and electron microscopy, histochemical staining, and, more recently, three-dimensional imaging and computational analysis to quantify layer number, thickness, and cell shapes. Different tissues exhibit characteristic Zelllagen that relate to their function. The term is primarily used in German-language histology literature, with English equivalents such as cell layers or layered epithelia.