正常肺的横切面(仅在右下肺的背面出现很少充血)。肺门淋巴结比较小，内部有大量炭末(吸入的炭末被肺巨噬细胞清除，并通过淋巴管，在淋巴结聚集。)，使其呈现灰黑色。
This is a cross-section of normal lung (with only minimal posterior congestion at the lower right). The hilar lymph nodes are small and have enough anthracotic pigment (from dusts in the air breathed in, scavenged by pulmonary macrophages, transferred to lymphatics, and collected in lymph nodes) to make them appear greyish-black.
