The DSC 1 is purely theory, and although it does cover deer biology and anatomy to some extent, it is generally delivered by means of a video gralloch.
DSC 1 candidates should go away with the basic knowledge of what is the minimum inspection required of the lymphatic system, and just as important, who to inform if they suspect a problem.
The main indicators are the Retropharangeal, sub-maxilliary and mesenteric glands.
However, the OP, having done his DSC 1 has seen fit to inspect the entire carcass and found something that he is uncertain of and has asked a valid question. He should be commended for this as there is no such thing as a stupid question.
I have pointed to the spleen and asked DSC 2 candidates what it is and its function. Some knew and some didn't, but it is not deemed as essential knowledge even for the purposes of DSC 2.
I would suspect that several people (including the OP) have gained more knowledge from this thread which is a bonus and one of the main benefits of a site such as this. We can all learn something new, but only if we are willing to learn.
MS