3. Circulation in Animals Transport systems functionally connect the organs of exchange with body cells. Transport systems functionally connect the organs of exchange with body cells. Diffusion is too slow. Diffusion is too slow. By rapidly transporting fluid in bulk it connects the aqueous environment of cells to organs of gas exchange. By rapidly transporting fluid in bulk it connects the aqueous environment of cells to organs of gas exchange. Nutrients are absorbed and wastes are taken away. Nutrients are absorbed and wastes are taken away.

4. Invertebrate Nutrient and Gas Exchange Gastrovascular Cavities Gastrovascular Cavities Cnidarians, Planarians, and Porifera Cnidarians, Planarians, and Porifera Circulation unnecessary because all cells are exposed to the environment. Circulation unnecessary because all cells are exposed to the environment.

5. Cnirdarians

6. Open Circulatory Systems Open circulatory system Open circulatory system Blood bathes organs directly Blood bathes organs directly Arthropods and most mollusks Arthropods and most mollusks No distinction between blood and interstitial fluid. No distinction between blood and interstitial fluid. Body fluid called hemolymph. Body fluid called hemolymph. Sinuses are spaces around organs. Sinuses are spaces around organs. One or more hearts pull blood in through ostia. One or more hearts pull blood in through ostia. Blood squeezed around the body through movement. Blood squeezed around the body through movement.

8. Closed Circulatory System Blood is confined to vessel and distinct from interstitial fluid. Blood is confined to vessel and distinct from interstitial fluid. Earth worms and higher animals. Earth worms and higher animals. Vertebrates have a cardiovascular system. Vertebrates have a cardiovascular system. Atrium – top chamber of the heart Atrium – top chamber of the heart Ventricle- lower chamber of the heart. Ventricle- lower chamber of the heart. Arteries – direct blood away from the heart. Arteries – direct blood away from the heart. Veins direct blood to the heart. Veins direct blood to the heart. Capillary beds infiltrate each tissue. Capillary beds infiltrate each tissue.

11. Systemic circuit – delivers blood to the body. Systemic circuit – delivers blood to the body. Pulmonary circuit – picks up blood from pulmonary organs and delivers it back to the heart. Pulmonary circuit – picks up blood from pulmonary organs and delivers it back to the heart.

12. Fish Heart Fish Fish Two chambers Two chambers Single circulation which means blood must travel through two capillary beds before it returns to the heart. Single circulation which means blood must travel through two capillary beds before it returns to the heart. Because pressure drops in the capillary bed, blood flow is much slower than in other organisms. Because pressure drops in the capillary bed, blood flow is much slower than in other organisms.

13. Amphibian Heart Three chambers Three chambers Two atria and one ventricle Two atria and one ventricle A ridge separates most of the oxygenated from the deoxygenated blood, however some mixing does occur. A ridge separates most of the oxygenated from the deoxygenated blood, however some mixing does occur. Double circulation Double circulation Blood returns to the heart after picking up oxygen. Sustains a higher pressure. Blood returns to the heart after picking up oxygen. Sustains a higher pressure. Pulmocutaneous circuit. Pulmocutaneous circuit. Pulmonary organs are the lungs and skin. Pulmonary organs are the lungs and skin. Reptiles Reptiles Three chambers clearly divided Three chambers clearly divided Have a pulmonary circuit Have a pulmonary circuit

14. Mammalian Heart Two atria and two ventricles Two atria and two ventricles Distinct separation of oxygen and deoxygenated blood. Distinct separation of oxygen and deoxygenated blood. Double circulation with a pulmonary circuit. Double circulation with a pulmonary circuit.

15. Mammalian Cardiac Cycle Cardiac Cycle - One complete pumping and filling. Cardiac Cycle - One complete pumping and filling. Systole – contraction phase of the cycle Systole – contraction phase of the cycle Diastole – relaxation phase of the cycle. Diastole – relaxation phase of the cycle. Cardiac Output – the volume of blood that the left ventricle pumps into the systemic circuit per minute. Cardiac Output – the volume of blood that the left ventricle pumps into the systemic circuit per minute. Depends on two factors: Depends on two factors: Heart rate - rate of heart beat. Heart rate - rate of heart beat. Stroke volume – blood pumped from left ventricle per contraction. Stroke volume – blood pumped from left ventricle per contraction.

16. Average stroke volume for humans is 75 ml with a cardiac output of about 5.25 L/min. and an average pulse of 70 beats per minute. Average stroke volume for humans is 75 ml with a cardiac output of about 5.25 L/min. and an average pulse of 70 beats per minute. Exercising increases stroke volume because the heart beats more efficiently. Exercising increases stroke volume because the heart beats more efficiently. More blood pumped to the systemic circuit per contraction. More blood pumped to the systemic circuit per contraction.

17. The “Lub Dub” Atrioventricular valves Atrioventricular valves Separate atria from ventricles. Separate atria from ventricles. Semilunar valves Semilunar valves Present at both exits of the heart. Present at both exits of the heart. Heart Murmur Heart Murmur Defect in the valves. Defect in the valves. “Lub” “Lub” Recoil of blood against closed atrioventricular valves. Recoil of blood against closed atrioventricular valves. “Dub” “Dub” Recoil of blood against closed semilunar valves Recoil of blood against closed semilunar valves

18. Maintaining the Beat Sinoatrial Node Sinoatrial Node Located in the right atrium near the Superior Vena Cava. Located in the right atrium near the Superior Vena Cava. Sets the tempo for contraction. Sets the tempo for contraction. Stimulates atrium to contract in unison. Stimulates atrium to contract in unison. Orchestration of muscle cells accomplished through intercalated discs. Orchestration of muscle cells accomplished through intercalated discs. Perkunji Fibers Perkunji Fibers Transmit electrical signal. Transmit electrical signal. 0.1 second delay allows atria to completely empty before the ventricles contract 0.1 second delay allows atria to completely empty before the ventricles contract

19. Maintaining the Beat Atriovenricular Node Atriovenricular Node Causes the ventricles to contract. Causes the ventricles to contract. Factors That Affect Heart Rate Factors That Affect Heart Rate Body temperature Body temperature 1 o F increase increases heart rate by 10 beats/min. 1 o F increase increases heart rate by 10 beats/min. Exercise Exercise Hormonal stimulation. Hormonal stimulation. Epinephrine –speeds up heart rate. Epinephrine –speeds up heart rate.

23. Arteries Thicker walls Thicker walls Outer wall connective tissue with elastic fibers Outer wall connective tissue with elastic fibers Middle layer smooth muscle – peristalsis Middle layer smooth muscle – peristalsis Inner wall – Endothelium, composed of smooth flat cells to reduce resistance to blood flow. Inner wall – Endothelium, composed of smooth flat cells to reduce resistance to blood flow.

24. Veins Thinner than arteries. Thinner than arteries. Valves to prevent back flow. Valves to prevent back flow. Blood moves through by muscle contractions. Blood moves through by muscle contractions. Virtually all pressure from ventricular contraction is gone. Virtually all pressure from ventricular contraction is gone.

25. Capillaries Lack outer and middle layers. Lack outer and middle layers. Basement membrane with endothelial layer. Basement membrane with endothelial layer. Designed for gas and nutrient exchange between blood and interstitial fluid. Designed for gas and nutrient exchange between blood and interstitial fluid. Blood flows 1000 times slower than in arteries and veins due to a large surface area. Blood flows 1000 times slower than in arteries and veins due to a large surface area. Facilitates gas exchange. Facilitates gas exchange. Pressure drops dramatically in capillary beds Pressure drops dramatically in capillary beds

29. Blood Pressure Hydrostatic pressure pushes blood through blood vessels. Hydrostatic pressure pushes blood through blood vessels. Systole – pressure due to ventricular contraction. Systole – pressure due to ventricular contraction. Arteries stretch because blood flows out much more quickly than it can leave the artery. Arteries stretch because blood flows out much more quickly than it can leave the artery. Diastole – pressure due to the arterial wall ”snapping back”. Diastole – pressure due to the arterial wall ”snapping back”. Next contraction occurs before all blood has left the artery and maintains pressure flow. Next contraction occurs before all blood has left the artery and maintains pressure flow.

30. Blood pressure determined by: Blood pressure determined by: Cardiac output Cardiac output Peripheral resistance Peripheral resistance Contraction of atrioles creates peripheral resistance. Contraction of atrioles creates peripheral resistance. Contractions triggered by stress, hormones, and nicotine. Contractions triggered by stress, hormones, and nicotine. Exercise increases cardiac output and dialates atrioles to supply blood to the muscles. Exercise increases cardiac output and dialates atrioles to supply blood to the muscles. Giraffes and probably dinasaurs have valves and sinuses in their brain and neck to prevent a stroke while bending down for a drink. Giraffes and probably dinasaurs have valves and sinuses in their brain and neck to prevent a stroke while bending down for a drink.

32. Gas Exchange in the Capillaries O 2 and CO 2 diffuse down their gradient. O 2 and CO 2 diffuse down their gradient. Hydrostatic pressure on the atriole end forces 80 % of the fluid out into the tissues. Hydrostatic pressure on the atriole end forces 80 % of the fluid out into the tissues. Large proteins and blood cells left behind increases the osmolarity of the blood. Large proteins and blood cells left behind increases the osmolarity of the blood. Causes fluid to move back into the capillaries at the venule end. Causes fluid to move back into the capillaries at the venule end. Fluid that doesn’t make it back into the cappilarie(15%) is returned to the blood through the lymphatic system. Fluid that doesn’t make it back into the cappilarie(15%) is returned to the blood through the lymphatic system.

35. Lymph Vessels Lymph fluid composition about the same as interstitial fluid. Lymph fluid composition about the same as interstitial fluid. Moves through the body by squeezing of skeletal muscles and peristalsis. Moves through the body by squeezing of skeletal muscles and peristalsis. Valves prevent back flow. Valves prevent back flow. Lypmph returns fluid that has leaked out in capillary beds to the circulatory system near the right atrium. Lypmph returns fluid that has leaked out in capillary beds to the circulatory system near the right atrium. Lymph contains white cells that attack bacteria and viruses. Lymph contains white cells that attack bacteria and viruses.

36. Plasma Composition of Plasma Composition of Plasma 90% H 2 O, inorganic salts(electrolytes) 90% H 2 O, inorganic salts(electrolytes) PH about 7.4 PH about 7.4 Plasma proteins Plasma proteins Buffers Buffers Fibrinogen(clotting) Fibrinogen(clotting) Proteins that escort lipids which are insoluble in water. Proteins that escort lipids which are insoluble in water. Hormones Hormones Viscosity proteins Viscosity proteins Kidneys maintain electrolytes. Kidneys maintain electrolytes.

37. Erythrocytes Biconcave for more surface area. Biconcave for more surface area. Lack mitochondria and nuclei – more room for hemoglobin. Lack mitochondria and nuclei – more room for hemoglobin. 250 million molecules of hemoglobin per cell. 250 million molecules of hemoglobin per cell. Generate ATP through anaerobic metabolism. Generate ATP through anaerobic metabolism. Kidneys produce erythropoietin to stimulate the function of RBC’s. Kidneys produce erythropoietin to stimulate the function of RBC’s. Hemoglobin also binds NO to relax capillaries. Hemoglobin also binds NO to relax capillaries.

39. RBC’S, Neutrophils

43. Blood Pressure Hydrostatic pressure pushes blood through blood vessels. Hydrostatic pressure pushes blood through blood vessels. Highest during ventricular contraction. Highest during ventricular contraction. During systole blood is pushed out into the artery faster than it can leave the artery. During systole blood is pushed out into the artery faster than it can leave the artery. During diastole artery “snaps back” and creates residual pressure in the arteries to continue pushing blood through. During diastole artery “snaps back” and creates residual pressure in the arteries to continue pushing blood through. Blood pressure is determined by cardiac output and peripheral resistance. Blood pressure is determined by cardiac output and peripheral resistance. Stress contracts blood vessels and raises blood pressure. Stress contracts blood vessels and raises blood pressure. Exercise causes atrioles to dialate causing more blood to flow in. A drop in pressure occurs and the cardiac output increases to compensate. Exercise causes atrioles to dialate causing more blood to flow in. A drop in pressure occurs and the cardiac output increases to compensate.

44. Cardiovascular Disease Thrombus – blood clot. Thrombus – blood clot. Embolus – when clot breaks off and moves elsewhere in the body. Embolus – when clot breaks off and moves elsewhere in the body. When a clot blocks a coronary artery – myocardial infarction. When a clot blocks a coronary artery – myocardial infarction. Atheroschlerosis – plaques form on the inner wall of the artery. Atheroschlerosis – plaques form on the inner wall of the artery. Arterioschlerosis – when plaques harden through calcification. Arterioschlerosis – when plaques harden through calcification. Angina Pectoris – heart pain that signals that theheart is not getting enough oxygen. Angina Pectoris – heart pain that signals that theheart is not getting enough oxygen.

45. Hypertension High Blood Pressure High Blood Pressure Causes chronic abuse of the endothelium and encourages plaque formation. Causes chronic abuse of the endothelium and encourages plaque formation. Narrows the lumen of the blood vessels and reduces elasticity of blood vessels. Narrows the lumen of the blood vessels and reduces elasticity of blood vessels. Can compromise aterial walls and increase risk for embolisms and anuerisms. Can compromise aterial walls and increase risk for embolisms and anuerisms.

46. Plaque Build-Up in Blood Vessels

48. Counter Current Exchange

52. Alveoli