BIOL 1202 Chapter : Bio 11 12
Document Summary
Transport systems functionally connect the organs of exchange with the body cells. Simple animals like cnidarians have a body wall only 2 cell layers thick, between the external environment and their gastrovascular cavity. The gastrovascular cavity functions in digestion and circulation. More complex animals have two types of circulatory systems. Open circulatory system: blood bathes the organs directly. Closed circulatory system: blood is confined to vessels and is distinct from the interstitial fluid. Both of these types of systems have 3 basic components. Allows blood and interstitial fluid to mix with each other. Does not have a heart to pump the blood. 42. 2 coordinated cycles of heart contraction drive double circulation in mammals. The rhythmic contraction and relaxation of the heart. Pacemaker cells: heart cells that regularly produce spontaneous electrical impulses. The impulses spread throughout cardiac muscle cells and stimulate them to contract. Gap junctions between cardiac muscle cells allow impulses to travel along atrial cells.
