This image shows the stratum spinosum and the so-called
"intercellular bridges" that are its hallmark feature.
A few of these are indicated by the arrows.
These "intercellular bridges" are an artifact of preparation, but they're so consistently present that they can reliably be used as an identifying characteristic of this layer; however, there is no continuity of cytoplasm between adjacent cells. The "bridges" are sites where the adjacent cells of the stratum spinosum are held together tightly by desmosomes. When the tissue is prepared for microscopy it shrinks, and the plasma membrane at these points stretches but remains firmly attached to its neighboring cell's membrane. The result is the ladder-like appearance of the intercellular space.
Monkey palm; H&E stain, 1.5 µm plastic section, 1000x
