1. Ch. 42 Circulation and gas Exchange

2. Open Circulatory System  Insects (other arthropods) and molluscs  No distinction between blood and interstitial fluid.  Hemolymph – body fluid  Body movements squeeze sinuses which moves hemolymph

3. Closed Circulatory System  Earthworms, squids, all vertebrates  Blood in vessels separate from interstitial fluid  Heart pumps blood into vessels.

4. Blood Vessels  Arteries – Blood Away from the heart  Veins – Blood to the heart  Capillaries – tiny vessels. Blood supply can vary depending on the site of capillaries.  Ex. Digestive system capillaries will fill with blood after a meal.

5. Components of Blood  Plasma, RBC (transport O 2 ), WBC (immune) and platelets.  Blood Clots caused by fibrin protein.  Self sealing material after a cut or scrape.