Where is the ductus arteriosus located?

The ductus arteriosus is a critical fetal blood vessel that connects the pulmonary artery to the descending aorta. This connection allows blood to bypass the lungs, which are not used for breathing in utero, as the fetus receives oxygenated blood directly from the mother through the placenta. After birth, the ductus arteriosus typically closes and forms a ligament, known as the ligamentum arteriosum.

The location of the ductus arteriosus is essential to understanding fetal circulation and the adaptations that occur at birth. Recognizing its placement helps in comprehending how blood flows through a developing fetus and how transitions happen postnatally. It facilitates the shunting of blood away from the lungs, directing it instead toward the aorta and systemic circulation, which is critical for the fetus's oxygen supply.