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!