1. The Cardiovascular System: Blood Vessels, Blood Flow and Blood Pressure

2. Flow and a Pressure Gradient
Figure 14.1
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.

3. Driving Force for Blood Flow
Figure 14.2
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.

4. Pressures of the Pulmonary and Systemic Circuit
Figure 14.3
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.

5. Effect of Resistance on Flow
Figure 14.4
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.

6. The Effect of Arteriole Radius on Blood Flow
Regulation of radius of arterioles (and small arteries)
Vasoconstriction
Decrease radius  increase resistance
Vasodilation
Increase radius  decrease resistance
Pulmonary circuit less resistance than systemic
Lower pressure gradient required for blood flow
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.

7. Total Peripheral Resistance
Combined resistance of all blood vessels within the systemic circuit
Resistance across a network of blood vessels depends on resistance of all vessels
Flow through network varies with resistance
Vasoconstriction in network  increase resistance  decrease flow
Vasodilation in network  decrease resistance  increase flow
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.

8. Relating Pressure Gradients and Resistance in the Systemic Circulation
Flow = P /R
Flow = cardiac output = CO
 P = mean arterial pressure = MAP
R = total peripheral resistance = TPR
CO = MAP / TPR
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.

9. Types of Blood Vessels Figure 14.5
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.

10. Blood Vessel Characteristics
Figure 14.6
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.

11. Arteries as Pressure Reservoirs
Figure 14.7a
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.

12. Arteries as Pressure Reservoirs
Figure 14.7b
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.

13. Compliance
Toolbox 14.1
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.

14. Blood Pressure Measurement
Systolic pressure
(beginning of sounds)
Diastolic pressure
(end of sounds)
Blood flow:
Sound:
No flow
No sound
Turbulent flow
Turbulent flow in compressed
artery makes audible
vibrations (Korotkoff sounds)
Korotkoff sounds
Laminar flow
Cuff pressure
between 70 and
110 mm Hg
Laminar flow in
noncompressed artery
makes no sounds
below 70 mm Hg
No blood flow
above
Pressure in the cuff
Stethoscope
Cuff
130
110 90 70 50
Time
Figure 14.8
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.

15. Blood Pressure in Vessels
Figure 14.9
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.

16. Radius Changes in Arterioles
Figure 14.10
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.

17. Arteriole Radius and Blood Flow
Flow varies due to differences in resistance
Figure 14.11b
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.

18. Active Hyperemia Increased blood flow Delivers more O2
Removes more CO2
Figure 14.12d
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.

19. Increased blood flow in response to a previous reduction in blood flow
Reactive Hyperemia
Increased blood flow in response to a previous reduction in blood flow
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.

20. Characteristics of Reactive Hyperemia
Blockage of blood flow to tissue
Metabolites increase and oxygen decreases
Vasodilation
Release blockage
Increased blood flow due to low resistance
Metabolites removed, oxygen delivered
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.

21. Active vs. Reactive Hyperemia
Local arteriolar
smooth muscle
O2 consumption
CO2 production
O2 Delivery
CO2 Removal
Vasodilation
Blood flow
O2 concentration
CO2 concentration
Resistance
Metabolic rate
Tissue
Negative
feedback
Active Hyperemia
(a)
Figure 14.13a
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.

22. Active vs. Reactive Hyperemia
Blood flow
Resistance
Reactive Hyperemia
Tissue
Local arteriolar
smooth muscle
O2 concentration
CO2 concentration
Vasodilation
O2 Delivery
CO2 Removal
Negative
feedback
(b)
Figure 14.13b
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.

23. The Myogenic Response Figure 14.14
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.

24. Blood Flow Patterns Figure 14.15a–b
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.

25. Extrinsic Control of Arteriole Radius and Mean Arterial Pressure
Flow = P/R
CO = MAP / TPR
MAP = CO x TPR
Mean arterial pressure depends on TPR
TPR depends on radius of arterioles
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.

26. Table 14.2
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.

27. Vessel Area and Velocity of Blood
Capillaries
Have greatest total cross-sectional area
Have slowest velocity of blood flow, enhances exchange
Figure 14.16
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.

28. Types of Capillaries Continuous capillaries Fenestrated capillaries
Most common
Small gaps between endothelial cells
Allows small water soluble molecules to move through
Fenestrated capillaries
Large gaps between endothelial cells forming pores or fenestrations
Allow proteins and in some cases blood cells to move through
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.

29. Continuous Capillary Figure 14.17a
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.

30. Fenestrated Capillary
Figure 14.17b
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.

31. Microcirculation Figure 14.18
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.

32. Capillary Exchange Figure 14.19
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.

33. Starling Forces Across Capillaries
Figure 14.20
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.

34. Vessel: Pressure / Volume Relation
Figure 14.21
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.

35. Blood Distribution Figure 14.22
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.

36. Importance of Central Venous Pressure
Pressure gradient between central veins and atria drives blood back to heart
Venous pressure – atrial pressure = 5 – 10 mm Hg
A decrease in venous pressure decreases driving force for venous return
Decrease in venous return  decreases end- diastolic volume  decreases stroke volume  decreases cardiac output  decreases blood flow to organs
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.

37. Factors of Venous Pressure
Figure 14.24
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings.