The Richter scale doesn't measure quake damage (see: Mercalli Scale) which is dependent on a variety of factors including population at the epicentre, terrain, depth, etc.
The circulatory system works with the muscular system, the nervous system, and the digestive system. The heart is a muscle so it is part of the muscular system. Also the heart and lungs have nerves so it is also part of the nervous system.
Time-saving video on the circulatory system. The circulatory system transports nutrients and blood cells to and from cells throughout the body. The circulatory systems includes veins, arteries and capillaries.