At what point should an edge loop terminate? Apologies if my question doesn't make sense, I'm new to this!

Should the highlighted edge loops on my model continue to the end of the extremeties? If so, why don't they?



Here's the same model with the faces highlighted if it helps. As you can see, the upper and lower faces are joined at the knuckle. Is this correct?



Thanks
Face loops only works with quad polygons which always have two opposing edges. A face loop does not depend on the shape of the quads face, it will always follow the opposing edge to the next face.

Edge loops are a bit more sophisticated. If you loop select a free edge (one that only touches one face) the loop will try to find other connected free edges. This depends on the angles of the edges. If you loop select a closed edge, it will try to find the opposing edge at any vertex, which works fine if four edges meet but not if five or three meet.