• ventricles
  • During development of the heart, the heart tissues undergo folding, and the truncus arteriosus is exposed to what will eventually be both the left and right ventricles. (wikipedia.org)
  • These two arteries receive blood from the ventricles and their semilunar valves permit blood to be forced into the arteries, and prevent backflow from the arteries into the ventricles. (wikipedia.org)
  • Blood mixes abnormally between the left and right ventricles and into the aorta. (wikipedia.org)
  • capillaries
  • While humans, as well as other vertebrates, have a closed cardiovascular system (meaning that the blood never leaves the network of arteries, veins and capillaries), some invertebrate groups have an open cardiovascular system. (wikipedia.org)
  • Arteries branch into small passages called arterioles and then into the capillaries. (wikipedia.org)