Aorta, small intestine and mesentery, gross specimen. The aorta (down left) is the body's main artery. It leads from the heart down through the chest and abdomen and supplies oxygenated blood to the body. The small intestine is a long coiled tube that is responsible for absorbing nutrients from food. The mesentery is a membranous tissue that connects the intestine to the abdominal wall and supplies it with blood.