The mesenteric lymph nodes lie between the layers of the mesentery. They vary from one hundred to one hundred and fifty in number, and may be grouped into three sets, viz.: 1  one lying close to the wall of the small intestine, among the terminal twigs of the superior mesenteric artery;he mesenteric lymph nodes lie between the layers of the mesentery. They vary from one hundred to one hundred and fifty in number, and may be grouped into three sets, viz.: 1  one lying close to the wall of the small intestine, among the terminal twigs of the superior mesenteric artery;