A friend tells you that she has tender, swollen “glands” along the left side of the front of her neck. You notice that she has a bandage on her left cheek that is not fully hiding a large infected cut...

A friend tells you that she has tender, swollen “glands” along the left side of the front of her neck. You notice that she has a bandage on her left cheek that is not fully hiding a large infected cut there. Exactly what are her swollen “glands,” and how did they become swollen?