Systemic circulatory system
Closed-loop network: arteries, arterioles, capillaries, venules, veins.
Functions: Transports oxygen, hormones, water, and nutrients to tissues; returns waste and CO2 to the heart.
Start of systemic circulation: Left ventricle pumps blood to aorta. Ascending aorta rises and arches left, becoming descending aorta in thorax and abdomen.
Major arterial branches: Right and left coronary arteries from ascending aorta -> heart. Brachiocephalic, left common carotid, left subclavian from aortic arch -> head, neck, arms. Descending aorta branches -> organs like liver, spleen, kidneys.
Microcirculation and return: Arteries -> arterioles -> capillaries for exchange. Blood drains into venules, merges into veins.
End of systemic circulation: Lower veins -> inferior vena cava. Upper veins -> superior vena cava. Both drain into right atrium.