Fig. 3
From: The lymphatic vascular system: much more than just a sewer
A Human Colon. Transition from the initial lymphatic in the basal mucosa to the precollector in the submucosa. Note the intraluminal valve in the precollector (arrow). (From: The human protein atlas [213]. B Human lymphatic collector from the hypodermis of the thigh. Note the strong muscular wall. L = lumen of the collector. C Transmission electron microscopy shows that the smooth muscle cells usually appear as electron-dense dark cells, while some have a light cytoplasm (asterisk). Bar = 45 µm in A, = 150 µm in B, and 4 µm in C