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

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

3. Major Arteries of Systemic Circulation
Figure 11.11
Slide 11.30
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

4. Major Veins of Systemic Circulation
Figure 11.12
Slide 11.31
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

5. Arterial Supply of the Brain
Figure 11.13
Slide 11.32
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

6. Hepatic Portal Circulation
Figure 11.14
Slide 11.33
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

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

8. Blood Pressure
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
Slide 11.36
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

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

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

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

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

13. Variations in Blood Pressure
Human normal range is variable
Normal
120 mm Hg systolic
80 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
Slide 11.41
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

14. Developmental Aspects of the Cardiovascular System
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
Slide 11.44
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings