1. Cardiovascular System at a Glance
Functions of Cardiovascular (CV) System
Distribute blood to whole body
Delivery of needed substances to cells
Removal of wastes
Organs of Cardiovascular System
Heart- pumps blood through the vessels
Arteries – carries blood away from the heart
Capillaries – exchange site between the blood and tissues
Veins – carries blood toward the heart

2. Anatomy and Physiology
Also called circulatory system
Maintains distribution of blood throughout body
Delivers oxygen and nutrients like glucose and amino acids to cells
Picks up carbon dioxide and other waste products from cells and delivers to lungs, liver, and kidneys for elimination

3. Anatomy and Physiology
Is composed of:
Heart
Blood vessels
Arteries
Capillaries
Veins
Divided into pulmonary circulation and systemic circulation

4. Systemic Circulation Between heart and cells of body
Carries oxygenated blood away from left side of heart to body
Carries deoxygenated blood from body to right side of heart

5. Pulmonary Circulation
Between heart and lungs
Carries deoxygenated blood away from right side of heart to lungs
Carries oxygenated blood from lungs to left side of heart

7. Heart
Muscular pump
Made up of cardiac muscle fibers
Could be called a muscle instead of an organ
Beats an average of 60 – 100 beats per minute (bpm), or about 100,000 times a day
Each time the muscle contracts:
Blood is ejected from heart
Pushed throughout body within blood vessels

8. Heart Located in the mediastinum, pericardial cavity
More to left side of chest
Directly behind sternum
About size of a fist
Shaped like upside-down pear
Tip of heart at lower edge
Called the apex

9. Medical Terminology: A Living Language, Fourth Edition
Bonnie F. Fremgen and Suzanne S. Frucht
Copyright ©2009 by Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
All rights reserved.

10. Heart Layers Endocardium Myocardium Epicardium Inner layer
Lines heart chambers
Smooth, thin layer that reduces friction as the blood passes through heart chambers
Middle layer
Thick muscle
Contraction of this layer develops the pressure required to pump blood through blood vessels
Outer layer
Forms the visceral layer of pericardial sac
Fluid between layers of pericardial sac reduces friction as heart beats

11. Heart Chambers Divided into four chambers
Two atria
Two ventricles
Heart is divided into right and left sides by a wall called the septum

12. Atria Left and right upper chambers Receiving chambers
Blood returns to atria in veins
Superior and inferior vena cava
Pulmonary veins

13. Ventricles Left and right lower chambers Pumping chambers
Thick myocardium
Blood exits ventricles into arteries
Aorta
Pulmonary artery

14. Heart Valves Tricuspid, pulmonary, mitral, aortic Four valves in heart
Act as restraining gates to control direction of blood flow
Found at entrance and exit to ventricles
Allow blood to flow only in forward direction by blocking it from returning to previous chamber

15. Tricuspid Valve An atrioventricular valve
Between right atrium and ventricle
Prevents blood in ventricle from flowing back into atrium
Has 3 leaflets or cusps

16. Pulmonary Valve A semilunar valve
Between right ventricle and pulmonary artery
Prevents blood in artery from flowing back into ventricle
Semilunar – valve looks like half moon

17. Mitral Valve An atrioventricular valve
Between left atrium and ventricle
Prevents blood in ventricle from flowing back into atrium
Also called bicuspid valve - has two cusps

18. Aortic Valve A semilunar valve Between left ventricle and aorta
Prevents blood in aorta from flowing back into ventricle

19. Figure 5.5 – Superior view of heart valves illustrating
Medical Terminology: A Living Language, Fourth Edition
Bonnie F. Fremgen and Suzanne S. Frucht
Copyright ©2009 by Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
All rights reserved.
Figure 5.5 – Superior view of heart valves illustrating
position, size, and shape of each valve.

20. Path of Blood Flow Through Heart
1. Deoxygenated blood from body enters relaxed right atrium via two large veins called:
Superior vena cava
Inferior vena cava

21. Path of Blood Flow Through Heart
2. Right atrium contracts
Blood flows through tricuspid valve into relaxed right ventricle

22. Path of Blood Flow Through Heart
3. Right ventricle contracts
Blood is pumped through pulmonary valve into pulmonary artery
Carries blood to lungs

23. Path of Blood Flow Through Heart
4. Relaxed left atrium receives blood that has been oxygenated by lungs
Blood enters left atrium from the four pulmonary veins

24. Path of Blood Flow Through Heart
5. Left atrium contracts
Blood flows through mitral valve into relaxed left ventricle

25. Path of Blood Flow Through Heart
6. Left ventricle contracts
Blood is pumped through the aortic valve and into aorta
Largest artery in the body
Carries blood to all parts of body

27. Systole and Diastole Heart chambers alternate between:
Relaxing to fill
Contracting to push blood forward
Relaxation phase is diastole
Contraction phase is systole

28. Conduction System of the Heart
Autonomic nervous system controls heart rate
Therefore, no voluntary control over heart
Special heart tissue conducts electrical impulses
Stimulate different chambers to contract in correct order

29. Path of the Conduction System
1. Sinoatrial (SA) node, or pacemaker, is where electrical impulse begins
From SA node a wave of electricity travels through atria
Causing them to contract, or go into systole

30. Path of the Conduction System
2. Next, atrioventricular node (AV) is stimulated
3. This node transfers stimulation wave to bundle of His

31. Path of the Conduction System
4. Electrical wave travels down bundle branches within interventricular septum
5. Finally, Purkinje fibers in ventricular myocardium are stimulated
Results in ventricular systole

32. Figure 5.7 – The conduction system of the heart.
Medical Terminology: A Living Language, Fourth Edition
Bonnie F. Fremgen and Suzanne S. Frucht
Copyright ©2009 by Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
All rights reserved.
Figure 5.7 – The conduction system of the heart.

33. Blood Vessels Pipes that circulate blood through body Three types:
Arteries
Capillaries
Veins
Lumen is the channel within blood vessels

34. Medical Terminology: A Living Language, Fourth Edition
Bonnie F. Fremgen and Suzanne S. Frucht
Copyright ©2009 by Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
All rights reserved.
Figure 5.9 – Comparative structure of arteries, capillaries, and veins.

35. Arteries Large thick-walled vessels
Wall contains smooth muscle and can dilate or constrict
As arteries travel through body they branch into progressively smaller vessels called arterioles

36. Arteries Carry blood away from heart
Towards either lungs or cells and tissues of body
Pulmonary artery carries deoxygenated blood to lungs
Aorta carries oxygenated blood to body
Coronary arteries supply myocardium

37. Capillaries
Network of tiny, thin-walled blood vessels called a capillary bed
Connecting unit between arteries and veins
Arterial blood flows into capillary bed
Venous blood flows out of capillary bed
Location for:
Oxygen and nutrients to diffuse out of blood
Carbon dioxide and wastes to diffuse into blood

38. Veins Much thinner walls than arteries
Much lower pressure system than in arteries
Have valves to insure blood flows only towards heart
Squeezing by skeletal muscles also assists blood return to heart
Smallest veins are called venules

39. Veins Carry blood towards the heart
From either the lungs or the cells and tissues of body
Pulmonary veins carry oxygenated blood from lungs
Superior and inferior vena cava carry deoxygenated blood from body

40. Blood Pressure
Measurement of force exerted by blood against walls of a vessel
May be affected by several characteristics of blood and blood vessels
Elasticity of arteries
Diameter of blood vessels
Viscosity of blood
Volume of blood
Amount of resistance to blood flow

41. Blood Pressure During ventricular systole During ventricular diastole
Blood is under great pressure
Gives highest pressure—systolic
Top number of blood pressure reading
During ventricular diastole
Blood isn’t being pushed from heart at all
Blood pressure drops to lowest point—diastolic
Bottom number of blood pressure reading