Pillbugs, also known as sowbugs, or woodlice, are familiar backyard creepy crawlies to most of us. Pillbugs are correctly. classified as terrestrial Isopods, and belong to the Class Crustacea. Familiar crustaceans include lobsters, crabs, shrimp, and daphnia (water fleas). The crustaceans, in turn, are part of a larger group, Arthropoda, or jointed-legged animals.
Video: Heart and circulatory system. Your heart is a pump. It's a muscular organ about the size of your fist and located slightly left of center in your chest. Your heart is divided into the right and the left side. The division protects oxygen-rich blood from mixing with oxygen-poor blood. Together, your heart and blood vessels comprise your cardiovascular system, which circulates blood and oxygen around your body. Your heart pumps about 5 quarts of blood every minute.
SSS is not a specific disease, but rather a group of signs or symptoms that indicate the sinus node, the heartâs natural pacemaker, is not functioning properly. A person with SSS may have a heart rhythm that is too slow (bradycardia), too fast (tachycardia), or one that alternates between the fast and slow (bradycardia-tachycardia). The sinus node is a specialized group of cells in the upper chamber of the heart, the atria, that creates electrical signals that regulate the pace and rhythm of the heartbeat.