The Cardiovascular System

1. The Cardiovascular System

2. The Cardiovascular System • A closed system of the heart and blood vessels • The heart pumps blood • Blood vessels allow blood to circulate to all parts of the body • Function: to deliver oxygen and nutrients and to remove carbon dioxide and other waste products

3. The Heart • Location • Thorax between the lungs • Pointed apex directed toward left hip • About the size of your fist • Less than 1 lb.

4. The Heart Figure 18.1 Page 677

5. The Heart: Coverings • Pericardium – a double serous membrane • Visceral pericardium • Next to heart • Parietal pericardium • Outside layer • Serous fluid fills the space between the layers of pericardium

6. The Heart: Heart Wall • Three layers • Epicardium • Outside layer • This layer is the parietal pericardium • Connective tissue layer • Myocardium • Middle layer • Mostly cardiac muscle • Endocardium • Inner layer • Endothelium http://www.ohiohealth.com/mayo/images/image_popup/r7_heartmuscle.jpg

7. The Heart: Heart Wall Figure 18.2 page 677 http://legacy.owensboro.kctcs.edu/gcaplan/anat2/notes/Image261.gif

8. External Heart Anatomy Fig 18.4 Pg 679

9. The Heart: Chambers • Right and left side act as separate pumps • Four chambers • Atria • Receiving chambers • Right atrium • Left atrium • Ventricles • Discharging chambers • Right ventricle • Left ventricle

10. Blood Circulation http://www.biomaterials.org/sigs/cardiovascular/images/cv_anatomy_heart.jpg

11. Blood Circulation Figure 18.5 Page 682

12. Flowchart for blood flow R. Atrium Pulmonary S.L. Valve Pulmonary Trunk R. Ventricle Tricuspid Valve Pulmonary Arteries Inferior Vena Cava (lower body) or Superior Vena Cava (upper body) Light Blue- Atrioventricular Valves Light Pink- Semilunar Valves Red- Oxygen RICH blood (oxygenated) Dark Blue- Oxygen POOR blood (deoxygenated) Purple- Gas Exchange Lungs Body where gas exchange occurs in capillaries Pulmonary Veins Aorta Aortic S.L. Valve L. Ventricle Bicuspid Valve L. Atrium

13. The Heart: Associated Great Vessels • Aorta • Leaves left ventricle • Pulmonary arteries • Leave right ventricle • Vena cava • Enters right atrium • Pulmonary veins (four) • Enter left atrium

14. http://static.howstuffworks.com/gif/adam/images/en/heart-front-view-picture.jpghttp://static.howstuffworks.com/gif/adam/images/en/heart-front-view-picture.jpg

15. The Heart: Valves • Allow blood to flow in only one direction • Four valves • Atrioventricular (AV) valves – between atria and ventricles • Bicuspid (mitral) valve (left) • Tricuspid valve (right) • Semilunar valves- between ventricle and artery • Pulmonary valve • Aortic valve http://www.starsandseas.com/SAS_Images/SAS_Physiol_Images/SAS%20cardiopics/heart_valves.jpg

16. http://www.trialsightmedia.com/exhibit_store/images/heart-valves.jpghttp://www.trialsightmedia.com/exhibit_store/images/heart-valves.jpg

17. The Heart: Valves • Valves open as blood is pumped through • Held in place by chordaetendineae (“heart strings”) • Close to prevent backflow • Lub Dub Heart Sound

18. http://www.clarian.org/ADAM/doc/graphics/images/en/19613.jpg

19. Operation of the Heart Valves Figure 18.9 and 18.10 pgs 686-7

20. The Heart: Conduction System • Intrinsic conduction system (nodal system) • Heart muscle cells contract, without nerve impulses, in a regular, continuous way • Special tissue sets the pace • Sinoatrial (SA) node (right atrium) • Pacemaker • Atrioventricular (AV) node • Junction of r&l atria and ventricles • Atrioventricular bundle (Bundle of His) • Bundle branches (right and left) • Purkinje fibers

21. Figure 18.14 page 691

22. Electrocardiograms (EKG/ECG) • Three formations • P wave: impulse across atria • QRS complex: spread of impulse down septum, around ventricles in Purkinje fibers • T wave: end of electrical activity in ventricles

23. EKGs/ECGs http://1.bp.blogspot.com/_aYa8XC4OPgQ/SdS8IubwZtI/AAAAAAAAA-w/_pg2lp_zQGw/s320/ecg03.gif http://www.virtualmedicalcentre.com/uploads/VMC/DiseaseImages/1287_ECG_Definitions3.jpg

24. The Heart: Cardiac Cycle • Atria contract simultaneously • Atria relax, then ventricles contract • Systole = contraction • Diastole = relaxation Figure 18.20 page 697

25. The Heart: Cardiac Cycle http://www.cartage.org.lb/en/themes/sciences/lifescience/generalbiology/physiology/CirculatorySystem/CirculatorySystem/TheHeart/cardiaccycle.gif

26. The Heart: Cardiac Output • Cardiac output (CO) • Amount of blood pumped by each side of the heart in one minute • CO = (heart rate [HR]) x (stroke volume [SV]) • Stroke volume • Volume of blood pumped by each ventricle in one contraction

27. The Heart: Cardiac Output • CO = HR x SV • 5250 ml/min = 75 beats/min x 70 mls/beat • Norm = 5000 ml/min • Entire blood supply passes through body once per minute. • CO varies with demands of the body.

28. Regulation of Heart Rate • Heart rate is normally determined by the pacemaker activity of the sinoatrial node (SA node) located in the posterior wall of the right atrium. • Stroke volume usually remains relatively constant • Changing heart rate is the most common way to change cardiac output

29. Regulation of Heart Rate • Increased heart rate • Sympathetic nervous system • Crisis • Low blood pressure • Hormones • Exercise • Decreased blood volume

30. Regulation of Heart Rate • Decreased heart rate • Parasympathetic nervous system • High blood pressure or blood volume • In Congestive Heart Failure the heart is worn out and pumps weakly.

31. Blood Vessels: The Vascular System • Taking blood to the tissues and back • Arteries • Arterioles • Capillaries • Venules • Veins

33. Differences Between Blood Vessel Types • Walls of arteries are the thickest • Lumens of veins are larger • Skeletal muscle “milks” blood in veins toward the heart • Walls of capillaries are only one cell layer thick to allow for exchanges between blood and tissue

34. Pulse • Pulse – pressure wave of blood • Monitored at “pressure points” where pulse is easily palpated

35. Blood Pressure http://0.tqn.com/f/p/440/graphics/images/en/9124.jpg

36. Blood Pressure • Systolic – pressure at the peak of ventricular contraction • Diastolic – pressure when ventricles relax • Pressure in blood vessels decreases as the distance away from the heart increases http://www.everybody.co.nz/admin/UserImages/479a5f19-d8cb-44a3-ac5e-544e695f8f20.jpg

37. Measuring Arterial Blood Pressure

38. Variations in Blood Pressure • Human normal range is variable • Normal • 140–110 mm Hg systolic • 80–75 mm Hg diastolic • Hypotension • Low systolic (below 110 mm HG) • Often associated with illness • Hypertension • High systolic (above 140 mm HG) • Can be dangerous if it is chronic

39. http://www.whatisnormalbloodpressure.org/systolic%20blood_pressure%20_and_chart/diastolic_systolic_blood_pressure.jpghttp://www.whatisnormalbloodpressure.org/systolic%20blood_pressure%20_and_chart/diastolic_systolic_blood_pressure.jpg

40. Virtual Body Interactive • Label the heart • Heart Valves • Conduction Animation • Blood Circulation Interactive • Blood Flow Animation • Cardiac Cycle Animation • Perform Open Heart Surgery!!! • Awesome website on the Cardiovascular system!