1. The Heart: Regulation of Heart Rate Slide 11.20 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Stroke volume usually remains relatively constant  Starling’s law of the heart – the more that the cardiac muscle is stretched, the stronger the contraction  Changing heart rate is the most common way to change cardiac output

2. The Heart: Regulation of Heart Rate Slide 11.21 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Increased heart rate  Sympathetic nervous system  Crisis  Low blood pressure  Hormones  Epinephrine  Thyroxine  Exercise  Decreased blood volume

3. The Heart: Regulation of Heart Rate Slide 11.22 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Decreased heart rate  Parasympathetic nervous system  High blood pressure or blood volume  Decreased venous return

4. Blood Vessels: The Vascular System Slide 11.23 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Taking blood to the tissues and back  Arteries  Arterioles  Capillaries  Venules  Veins

5. The Vascular System Slide 11.24 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 11.8b

6. Blood Vessels: Anatomy Slide 11.25 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Three layers (tunicas)  Tunica interna  Endothelium  Tunica media  Smooth muscle (smaller in veins)  Controlled by sympathetic nervous system  Tunica externa  Mostly fibrous connective tissue

7. Differences Between Blood Vessel Types Slide 11.26 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Walls of arteries are the thickest  Lumens of veins are larger  Walls of capillaries are only one cell layer thick to allow for exchanges between blood and tissue

8. Movement of Blood Through Vessels Slide 11.27 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Most arterial blood is pumped by the heart  Veins use the milking action of muscles to help move blood Figure 11.9

9. Capillary Beds Slide 11.28a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Capillary beds consist of two types of vessels  Vascular shunt – directly connects an arteriole to a venule Figure 11.10

10. Capillary Beds Slide 11.28b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  True capillaries – exchange vessels  Oxygen and nutrients cross to cells  Carbon dioxide and metabolic waste products cross into blood Figure 11.10

11. Circulation to the Fetus Slide 11.34 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 11.15

12. Pulse Slide 11.35 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Pulse – pressure wave of blood  Monitored at “pressure points” where pulse is easily palpated Figure 11.16

13. Blood Pressure Slide 11.36 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Measurements by health professionals are made on the pressure in large arteries  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

14. Measuring Arterial Blood Pressure Slide 11.37 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 11.18

15. Comparison of Blood Pressures in Different Vessels Slide 11.38 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 11.17

16. Blood Pressure: Effects of Factors Slide 11.39a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Neural factors  Autonomic nervous system adjustments (sympathetic division)  Renal factors  Regulation by altering blood volume  Renin – hormonal control

17. Blood Pressure: Effects of Factors Slide 11.39b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Temperature  Heat has a vasodilation effect  Cold has a vasoconstricting effect  Chemicals  Various substances can cause increases or decreases  Diet

18. Factors Determining Blood Pressure Slide 11.40 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 11.19

19. Variations in Blood Pressure Slide 11.41 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  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

20. Capillary Exchange Slide 11.42 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Substances exchanged due to concentration gradients  Oxygen and nutrients leave the blood  Carbon dioxide and other wastes leave the cells

21. Capillary Exchange: Mechanisms Slide 11.43 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Direct diffusion across plasma membranes  Endocytosis or exocytosis  Some capillaries have gaps (intercellular clefts)  Plasma membrane not joined by tight junctions  Fenestrations of some capillaries  Fenestrations = pores

22. Diffusion at Capillary Beds Slide 11.29 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 11.20

23. Homeostatic Imbalances of the Cardiovascular System Slide 11.44 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  CHF (congestive heart failure)— progressive condition reflects coronary atherosclerosis, persistent high BP, or multiple myocardial infarcts  Varicose Veins—pooling of blood in feet and legs, inefficient venous return  Hypertension—high BP  Hypotension—low BP

24. Homeostatic Imbalances of the Cardiovascular System Slide 11.44 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Atherosclerosis—small, fatty mounds of muscle protrude into vessel wall  Arteriosclerosis—end stage of atherosclerosis, hardening of plaques, increased rigidity of vessels  Coronary artery disease—filling of blood vessels with fatty, calcified deposits

25. Developmental Aspects of the Cardiovascular System Slide 11.44 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  A simple “tube heart” develops in the embryo and pumps by the fourth week  The heart becomes a four-chambered organ by the end of seven weeks  Few structural changes occur after the seventh week