Trace the pathway of blood to and from the brain in the systemic circuit. (pages \(102-04\) )

The pathway of blood to and from the brain in the systemic circuit begins at the left ventricle, which pumps oxygen-rich blood into the aorta. From the aorta, blood flows to the brain through the common carotid arteries, which divide into internal and external carotid arteries. The internal carotid arteries supply blood directly to the brain and form the Circle of Willis, an arterial network ensuring blood flow to vital brain areas. Nutrient exchange occurs in the brain's capillary beds, and the now deoxygenated blood returns to the heart through veins like the internal jugular veins. These veins merge and form the superior vena cava, which drains the blood into the right atrium. Lastly, the blood is pumped to the lungs for oxygenation and returns to the left atrium, completing the blood circulation cycle.