The microscopic layers and cell types of the alveolar-capillary blood-air barrier in the human lung.

The structural components and temporary timber falsework used in traditional masonry arch construction.

The main mechanical components and structural sections of a modern tunnel-boring machine.

Anatomy of a splendid alfonsino, Beryx splendens

Austria: boundaries + states + names

The four main color-coded recycling and waste bins alongside common household items sorted into each category.

The seven main regions of the electromagnetic spectrum arranged in order of decreasing wavelength and increasing frequency.

The gravitational interaction between the Earth and the Moon that generates high and low ocean tides.

The primary structural elements and fastening hardware of a standard steel column base connection.

The main chambers, valves, and blood vessels showing the path of circulation through the human heart.