The mesenteric arteries take blood from the aorta and distribute it to a large portion of the gastrointestinal tract. Both the superior and inferior mesenteric arteries arise from the abdominal aorta. Each of these arteries travel through the mesentery, within which they branch several times before reaching the gut. In humans, many of these branches are named, but in smaller animals the branches are more variable. In some animals, including humans, branches of these arteries join with the marginal artery of the colon, which means that occlusion of one of the main arteries does not necessarily lead to the death of the part of the gut that it usually supplies.