1. 1 Cardiovascular System Chapter 13

2. 2 I. Structure of the Heart A. Average size: 14 cm long and 9 cm wide B. Found between the lungs, anterior to the vertebral column and posterior to the sternum C. Pericardium: encloses the heart Fibrous pericardium is the outmost layer Parietal pericardium is the middle layer Visceral pericardium covers the heart Pericardial cavity lies between the parietal and visceral layers and reduces friction on the heart

3. 3 D. Heart Wall Epicardium (outer): connective tissue Myocardium (middle): cardiac muscle tissue Endocardium (inner): epithelium and connective tissue

4. 4 E. Heart Chambers Atria: 2 upper chambers that receive blood Ventricles: 2 lower chambers that force blood out of the heart; right ventricle has a smaller muscular wall Septum: wall between left and right chambers Atrioventricular valve (A-V valve) ensures one- way blood flow Tricuspid lies between the right atrium and ventricle

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6. 6 What’s “sinus rhythm”?

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8. 8 The electrical impulses travel from the SA node and to the AV node with the successful contraction of the atria. The electrical impulses from the AV node successfully contract the ventricles. http://pediatriccardiology.uchicago.edu/PP/a bnl%20rhythm%20for%20parents%20body. htm http://pediatriccardiology.uchicago.edu/PP/a bnl%20rhythm%20for%20parents%20body. htm http://www.cocukkalbi.net/oskultasyon.swf

9. 9 Superior Vena Cava and Inferior Vena Cava (veins) deliver blood to right atrium along with a smaller coronary sinus vein Pulmonary Valve: valve at base of right ventricle Pulmonary Veins: blood from lungs to left atrium Bicuspid Valve: valve between left atrium and ventricle Aorta: blood exits left ventricle to the aorta Aortic valve: valve at base of left ventricle

10. 10 F. Blood Flow Right Atrium  Tricuspid valve  Right Ventricle  Pulmonary valve  Pulmonary trunk  (lungs)  Pulmonary veins  Left atrium  Bicuspid Valve  Left Ventricle  Aortic valve  Aorta Where in this flow is the blood oxygenated? Un- oxygenated?

11. 11 G. The heart needs blood too! Coronary arteries: the first two branches of the aorta that supply blood to the heart

12. 12 II. The Cardiac Cycle A. Systole: atria contractions B. Diastole: ventricles relax C. The cardiac cycle is the series of events that constitute the heart beat 1. atria contract/ventricles relax 2. ventricles contract/atria relax 3. atria and ventricles relax D. Cardiac Conduction system: muscle fibers in the myocardium that coordinate the events of the cardiac cycle

13. 13 E. Electrocariogram (ECG): recording of the electrical changes that occur in the myocardium during the cardiac http://www.youtube.com/watch?v=u6saTO8 _o2g http://www.youtube.com/watch?v=u6saTO8 _o2g How do you take “blood pressure”?

14. 14 What’s normal for blood pressure? http://www.nlm.nih.gov/medlineplus/highbloodpres sure.html http://www.nlm.nih.gov/medlineplus/highbloodpres sure.html What is hypertension? What are some of the problems associated with high blood pressure? What is preeclampsia? How is high blood pressure treated? Who is at risk for hypertension? Are certain groups of people more at risk for hypertension than others? Explain?

15. 15 III. Blood Vessels A. Close circuit of tubes that carry blood to the cells and back again B. Arteries: carries blood away from the heart Arterioles: smaller arteries Three layers: Tunica interna (innermost layer); mostly epithelial tissue Tunica media (middle layer); mostly smooth muscle tissue Tunica externa (outermost layer); connective tissue

16. 16 Vasoconstriction: smooth muscles contract, reducing vessel diameter Vasodilation: smooth muscles relax; increasing vessel diameter C. Capillaries: smallest diameter blood vessels Connect the smallest arterioles and venules Walls of these vessels allow for substances to move into the fluid surrounding the tissue

17. 17 D. Veins: carry blood back to the heart Venules: vessels that connect to the capillaries Same three layers as the arteries, yet less developed middle layer Table 13.2

18. 18 IV. Blood Pressure A. The force blood exerts against the inner walls of blood vessels Arterial blood pressure rises and falls with the cardiac cycle Systolic pressure: max pressure during ventricular contraction Diastolic pressure: lowest pressure

19. 19 B. Factors effecting Blood Pressure Heart Action: stroke volume: the amount of blood released from the left ventricle Cardiac output=stroke volume x heart rate per minute Blood Volume Peripheral Resistance: friction between the blood and the walls of the blood vessels Blood Viscosity

20. 20 C. Regulation of Blood Pressure Regulation of cardiac output Regulation of peripheral resistance

21. 21 V. Circulation A. Pulmonary Circuit: the vessels that carry blood from the heart to the lungs and back again Pulmonary Trunk  Right/Left Pulmonary Arteries  Right/Left Lungs  Pulmonary capillaries  Venules  Pulmonary Veins (4 total, 2 from each side)  Left atrium

22. 22 B. Systemic Circuit: oxygenated blood from left atrium enters the left ventricle and is forced out the aorta Leads to the tissues of the body Returns from the tissues of the body to the right atrium

23. 23 VI. Arteries and Veins System A. Aorta: largest diameter artery B. Figure 13.32- Arterial System C. Figure 13.36- Venous System