Lines of Zahn

Lines of Zahn are a characteristic of thrombi that appear when formed in the heart or aorta. They have visible and microscopic laminations produced by alternating pale layers of platelets mixed with fibrin and darker layer containing red blood cells. Their significance implies thrombosis at a site of rapid blood flow. In veins or smaller arteries, where flow is not as constant, they are less apparent.

Etymology
They are named after German pathologist Friedrich Wilhelm Zahn (1845-1904).