Fig. 2
From: Morphometric characterisation of human tracheas: focus on cartilaginous ring variation
a Diagram illustrating where the three points of measurement for each ring were taken for thickness and height. The right end (blue) and left end (purple) measurements are taken 6 mm from the cartilage-trachealis border. b Diagram illustrating width and A-P measurements, and the associated cross-sectional ring shapes (U, C, D). Blue line: A-P diameter. Red line: width