Circulation Read Chapter Blood Blood carries to the cells  Oxygen produced by R______________  Nutrients processed by D_____________ Blood carries away waste materials from the cells  Carbon dioxide taken to the L_______  Urea, taken to the K_________ Blood also transports  Hormones(molecules that regulate the function of tissue or organs)  Enzymes(molecules that catalysis reactions)  Antibodies(protein that are on B-cells and attach to & kill foreign bodies)

What is blood made up of?  Plasma, mostly water. carries dissolved molecules & plasma proteins for clotting  Red blood cells transport O 2 in hemoglobin, no nucleus, can’t repair them selves. Have a 120 day life-span White blood cells, defend body against invaders

The shape of blood cells

Blood clotting When plasma comes into contact with tissue it reacts to produce a protein (fibrin) which clump together to form a mesh which traps red blood cells & platelets to form a clot.

The Cardiovascular System This is the Heart & blood vessels The Blood vessels: ArteriesCarries blood away from heart to the body. Thick, tough elastic walls to withstand high pressure VeinsCarries blood to the heart from the body. Have larger passageways. CapillariesVery fine blood vessels where exchange of substances between the blood & cells occurs. Most molecules leave capillaries by diffusion or bulk flow. Fluids renter the capillaries by osmosis

Pulmonary vein Blood moves from _________ To _______________ Pulmonary artery Blood moves from _________ To _______________ Aorta Blood moves from _________ To _______________ Superior vena cava Blood moves from _________ To _______________ Inferior vena cava Blood moves from _________ To _______________

The Heart The heart has evolved from the simple two chambered heart in fish to the three chambered heart in amphibians to our four chambered heart. Disadvantages of the fish heart  Not enough power to make blood flow fast after the gills Advantages of our heart  More efficient  Higher pressure  Higher metabolic rate & so higher levels of activity Relatively constant body temperature

Structure of the Heart The interior of the Heart is divided into 4 chambers Right atriumDeoxygenated blood from the body enters here via the superior & inferior veins. Left atriumOxygenated blood returning from the lungs enters here via the pulmonary vein. Right ventriclePropels deoxygenated blood through the pulmonary arteries to the capillaries of the lungs Left ventriclePropels oxygenated blood through the aorta to the capillaries in body tissue ValvesStop back flow of blood between the chambers & also back into the blood vessels during contraction

The atria are thin walled so they can expand to take in blood & both contract at the same time to push blood through the valves into the ventricles. The ventricles contract simultaneously, this closes the valves preventing back flow The healthy heart of an adult beats 70 times a minute at rest