In the middle of each kidney there is an indentation that forms the renal hilum.

每个肾中部有凹陷的肾门。

It's called the hilum, and it's where the seed was attached to its parent plant.

它叫做种脐，是种子附着在母株上的地方。

You also don't see large lymph nodes in the mediastinum or near the hilum or central part of the lung, which are often seen in other types of pneumonia.

另外，纵隔、肺门或者肺中部淋巴结肿大也很少出现，而这些在其它类型的肺炎中则很常见。