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Circulatory System in Animals Regents Biology 2008-2009 Feeding Energy Needs Why do we need a circulatory system? supplies in fuel (sugars) digestive system oxygen respiratory system waste out CO2 respiratory system need to pick up & deliver the supplies & wastes around the body Regents Biology circulatory system Simple organisms When your body is only 2-cell layers thick, you can get supplies in and waste out just through diffusion all cells within easy reach of fluid Regents Biology Jellyfish Hydra Complex organisms Circulatory system made up of 3 parts organ heart tissues & cells blood vessels arteries veins capillaries blood red blood cells plasma Regents Biology Circulatory systems All animals have: muscular pump = heart tubes = blood vessels circulatory fluid = “blood” open hemolymph Regents Biology closed blood Vertebrate Heart 4-Chambered heart atria (atrium) thin wall collection chamber left atrium receive blood ventricles thick wall pump right pump blood out atrium Regents Biology right ventricle left ventricle Evolution of circulatory system Not everyone has a 4-chambered heart fish 2 chamber V amphibian 3 chamber A A A V Regents Biology reptiles 3 chamber A V A V birds & mammals 4 chamber A V A V Lub-dub, lub-dub 4 valves in the heart flaps of connective tissue prevent backflow Heart sounds closing of valves “Lub” SL AV AV force blood against closed AV valves “Dub” force of blood against semilunar valves Heart murmur leaking valve causes hissing sound blood squirts backward through valve Regents Biology Electrical signals allows atria to empty completely before ventricles contract stimulates ventricles to contract from bottom to top, driving blood into arteries heart pumping controlled by electrical impulses Biology Regents signal also transmitted to skin = EKG Cardiac Cycle ventricles fill How is this reflected in blood pressure measurements? systolic ________ diastolic chambers fill pump (peak pressure) _________________ fill (minimum pressure) Regents Biology 110 ________ 80 ventricles pump Measurement of blood pressure if systolic > 150 hypertension = or (high blood pressure) if diastolic > 90 Regents Biology Have a heart? 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Regents Biology 2008-2009 Circulatory System Blood Vessels Regents Biology 2008-2009 Blood vessels arteries veins artery venules arterioles arterioles capillaries venules veins Regents Biology Arteries: Built for their job Arteries blood flows away from heart thicker walls provide strength for high pressure pumping of blood elastic & stretchable maintains blood pressure even when heart relaxes Regents Biology Major arteries aorta carotid = to head to brain & left arm to right arm to body pulmonary artery pulmonary coronary artery = arteries to lungs Regents Biology Coronary artery bypass bypass surgery Regents Biology Veins: Built for their job Veins Blood flows toward heart blood returns back to heartOpen valve thinner-walled blood travels back to heart at low speed & pressure why low pressure? far from heart blood flows because muscles contract when we move Closed valve squeeze blood through veins valves in large veins in larger veins one-way valves Regents Biology allow blood to flow only toward heart Major Veins superior vena cava = from upper body pulmonary vein = from lung inferior Regentsvena Biology cava = from lower body pulmonary vein = from lung Structure-function relationship Capillaries very thin walls allows diffusion of materials across capillary O2, CO2, H2O, waste body cell CO2 food, waste O2 food Regents Biology Circulation of Blood Circulation to lungs 2 part system Circulation to lungs lungs blood gets O2 from lungs drops off CO2 to lungs brings O2-rich blood from lungs to heart heart Circulation to body pumps O2-rich blood to body picks up nutrients from digestive system collects CO2 & cell wastes Regents Biology body Circulation to body Vertebrate circulatory system 2 part system lungs artery to lungs vein from lungs to heart heart vein from body to heart body Regents Biology artery to body Stops along the way… Lungs pick up O2 / clean out CO2 Small Intestines pick up nutrients from digested food Large Intestines pick up water from digested food Liver clean out worn out blood cells Regents Biology More stops along the way… Kidneys filters out wastes (urea) extra salts, sugars & water Bone picks up new red blood cells Spleen picks up new white blood cells Regents Biology Circulatory System & Homeostasis ATP Homeostasis keeping the internal environment of the body balanced need to balance food & O2 in need to balance energy (ATP) production need to balance CO2 & waste out Exercise heart beat faster food O2 CO2 waste need more ATP bring in more O2 & food; remove more CO2 & waste out Disease poor lung or heart function = heart beat faster need to work harder to bring in O2 & food & remove wastes Regents Biology Have a heart? 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Regents Biology 2008-2009 Circulatory System Blood Regents Biology 2008-2009 Blood & blood cells Blood is a tissue of fluid & cells plasma liquid part of blood dissolved salts, sugars, proteins, and more cells red blood cells (RBC) transport O2 in hemoglobin white blood cells (WBC) defense & immunity platelets blood clotting Regents Biology Blood Cell production ribs, vertebrae, breastbone & pelvis Stem cells “parent” cells in bone marrow differentiate into many different types of cells Regents Biology white blood cells white blood cells red blood cells Red blood cells Small round cells produced in bone marrow 5 liters of blood in body 5-6 million RBC in drop of human blood last 3-4 months (120 days) filtered out by liver ~3 million RBC destroyed each second Regents Biology Hemoglobin Protein which carries O2 250,000 hemoglobins in 1 red blood cell O2 O2 Regents Biology O2 O2 emergency repair of circulatory system Blood clotting chemical emergency signals Regents Biology platelets seal the hole protein fibers build the clot Cardiovascular disease Atherosclerosis & Arteriosclerosis deposits inside arteries (plaques) develop in inner wall of the arteries, narrowing their channel increase blood pressure increase risk of heart attack, stroke, kidney damage normal artery Regents Biology hardening of arteries Cardiovascular health Risk Factors genetics diet high animal fat exercise & lifestyle smoking lack of exercise Regents Biology bypass surgery Heart Disease Heart disease death rates 1996-2002 Adults ages 35 and older Regents Biology Women & Heart Disease Death rates for heart disease per 100,000 women, 2002 Risk factors Smoking Lack of exercise High fat diet Overweight Heart disease is 3rd leading cause of death among women aged 25–44 years & 2nd leading cause of death among women aged 45–64 years. Regents Biology Have a heart? Ask Questions!! Regents Biology 2008-2009