Representative image of lymphatic vessels organization on the pleural side of rat diaphragm, after the in vivo staining with a FITC-conjugated fluorescent tracer. Lymph enters lymphatic lacunae (asterisks) and then is propelled through vessels longitudinally (L) and/or perpendicularly (P) arranged with respect to the skeletal muscle fibers orientation. Lymphatic collectors located at the muscle periphery, next to the costal margin, are typically organized in complex loop structures (loop) and display intrinsic contractility. Scalebar 1 mm.