1. Section Outline 37–1 The Circulatory System
A. Functions of the Circulatory System
B. The Heart
1. Circulation Through the Body
2. Circulation Through the Heart
3. Heartbeat
C. Blood Vessels
1. Arteries
2. Capillaries
3. Veins
D. Blood Pressure
E. Diseases of the Circulatory System
1. High Blood Pressure
2. Consequences of Atherosclerosis
3. Circulatory System Health

2. Questions to be answered
What are the structures of the circulatory system?  
What are the three types of blood vessels in the circulatory system?

3. Vocabulary to know for the chapter
valve pacemaker aorta artery capillary vein atherosclerosis
myocardium atrium ventricle pulmonary circulation systemic circulation

4. 37–1 The Circulatory System
A. Functions of the Circulatory System
• The human circulatory system consists of the heart, a series of blood vessels, and the blood that flows through them

5. B. The Heart
• A picture of the structures of the Heart is found on page 944 in your book
• Myocardium – thick layer of muscle that the powerful contractions pump blood through the circulatory system.

6. Figure 37-3 The Structures of the Heart
Section 37-1
Inferior Vena Cava
Vein that brings oxygen-poor blood from the lower part of the body to the right atrium
Tricuspid Valve
Prevents blood from flowing back into the right atrium after it has entered the right ventricle
Pulmonary Valve
Prevents blood from flowing back into the right ventricle after it has entered the pulmonary artery
Pulmonary Veins
Bring oxygen-rich blood from each of the lungs to the left atrium
Superior Vena Cava
Large vein that brings oxygen-poor blood from the upper part of the body to the right atrium
Aorta
Brings oxygen-rich blood from the left ventricle to the rest of the body
Pulmonary Arteries
Bring oxygen-poor blood to the lungs
Aortic Valve
Prevents blood from flowing back into the left ventricle after it has entered the aorta
Mitral Valve
Prevents blood from flowing back into the left atrium after it has entered the left ventricle
Left Atrium
Right Atrium
Left Ventricle
Septum
Right Ventricle

7. 1. Circulation Through the Body
 Pulmonary circulation – pathway of oxygen-poor blood that pumps from heart to lungs
 Systemic circulation – pathway oxygen rich blood is pumped from the heart to rest of the body

8. Figure 37-2 The Circulatory System
Section 37-1
Capillaries of head and arms
Capillaries of abdominal organs and legs
Inferior vena cava
Pulmonary vein
Capillaries of right lung
Superior vena cava
Aorta
Pulmonary artery
Capillaries of left lung

9. 2. Circulation Through the Heart
 Valves – flaps of connective tissue between atria and the ventricles
 Creates one way traffic of blood

10. 3. Heartbeat
 Two networks of muscle fibers in the heart, one in the atria and the other in the ventricles
 Pacemaker – the nodes that start heart muscle contraction
 The Sinoatrial node starts the wave for the heart muscle contraction

11. The Sinoatrial Node Section 37-1 Contraction of Atria
Contraction of Ventricles
Sinoatrial (SA) node
Conducting fibers
Atrioventricular (AV) node

12. C. Blood Vessels
Aorta – the first of a series of blood vessels that carry the blood on its round trip through body and back to the heart
1. Arteries
 Arteries - large vessels that carry blood form the heart to the tissues of the body
 Most of the time filled with oxygen-rich blood

13. 2. Capillaries
 Capillaries are the smallest of the blood vessels.
 The walls can be 1 cell thick
 Bring nutrients and oxygen to the needed areas and absorb waste products and carbon dioxide
3. Veins
 Veins – vessels that return blood back to the heart
 many are located between skeletal muscle this way every time you contract you push blood back to the heart

14. Figure 37-5 The Three Types of Blood Vessels
Section 37-1
Artery
Vein
Connective tissue
Smooth muscle
Endothelium
Valve
Venule
Arteriole
Capillary

15. E. Diseases of the Circulatory System
Atherosclerosis – condition in which fatty deposits called plaque build up on the inner walls of the arteries. This can cause a blockage in the blood vessels causing a heart attack of stroke
1. High Blood Pressure
A.K.A hypertention, forces the heart to work harder and might wear out quicker
2. Consequences of Atherosclerosis
Blood clots, can be seen blood shot eyes
Heart attack
Stroke

16. 3. Circulatory System Health
Cardiovascular diseases are easier to prevent that to cure
Exercise, control weight, reduce stress
Diet of low saturated fat and cholesterol
Cardiovascular diseases are also reduced by not smoking

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