Pathologists compare a patient's tissue sample against the "normal" structures found in an atlas to identify diseases like cancer or inflammation.

The Atlas of Human Histology: Mapping the Microscopic Universe

By seeing the shape and arrangement of cells, we can understand how they work—for example, how the thin walls of lung alveoli facilitate rapid gas exchange.

A standard atlas is typically organized around the four fundamental tissue types that constitute every organ in the body:

The vivid colors seen in these atlases aren't natural; they are the result of ingenious staining techniques. The most common is . Hematoxylin stains cell nuclei a deep purple, while Eosin colors proteins and cytoplasm various shades of pink. Other methods, like the Periodic Acid-Schiff (PAS) stain, are used to highlight specific components like carbohydrates. Why These Atlases Matter

The specialized tissues responsible for movement, from the heart to the limbs.

The protective sheets that line our surfaces and cavities.