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Essentials of Human Anatomy & Physiology

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Slides 11.1 – 11.19

Seventh Edition

Elaine N. Marieb

Chapter 11

The Cardiovascular System

Lecture Slides in PowerPoint by Jerry L. Cook

INTERESTING FACTS ABOUT THE HEART

. . .

• http://www.webmd.com/heart/features/amazing-

facts-about-heart-health-and-heart-disease_

The Cardiovascular SystemThe Cardiovascular System

Slide 11.1Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

• A closed system of the heart and blood vessels

• The heart pumps blood

• Blood vessels allow blood to circulate to all parts of the body

• The function of the cardiovascular system is to deliver oxygen and nutrients and to remove carbon dioxide and other waste products

The HeartThe Heart

Slide 11.2aCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

• Location

• Thorax between the lungs

• Pointed apex directed toward left hip

• About the size of your fist

The HeartThe Heart

Slide 11.2bCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Figure 11.1

The Heart: CoveringsThe Heart: Coverings

Slide 11.3Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

• Pericardium – a double serous membrane

• Visceral pericardium

• Next to heart

• Parietal pericardium

• Outside layer

• Serous fluid fills the space between the layers of pericardium

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Heart Covering

• Pericardial physiology

• Protects and anchors heart

• Prevents overfilling

Figure 19.2

The Heart: Heart WallThe Heart: Heart Wall

Slide 11.4Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

• Three layers

• Epicardium

• Outside layer

• This layer is the parietal pericardium

• Connective tissue layer

• Myocardium

• Middle layer

• Mostly cardiac muscle

• Endocardium

• Inner layer

• Endothelium

External Heart AnatomyExternal Heart Anatomy

Slide 11.5Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 11.2a

The Heart: ChambersThe Heart: Chambers

Slide 11.6Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

• Right and left side act as separate pumps

• Four chambers

• Atria

• Receiving chambers

• Right atrium

• Left atrium

• Ventricles

• Discharging chambers

• Right ventricle

• Left ventricle

Atria of the Heart

• Atria are the receiving chambers of the heart

• Each atrium has a protruding auricle

• Pectinate muscles mark atrial walls

• Blood enters right atria from superior and inferior venae cavae and coronary sinus

• Blood enters left atria from pulmonary veins

Ventricles of the Heart

• Ventricles are the discharging chambers of the

heart

• Papillary muscles and trabeculae carneae muscles

mark ventricular walls

• Right ventricle pumps blood into the pulmonary

trunk

• Left ventricle pumps blood into the aorta

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Blood CirculationBlood Circulation

Slide 11.7Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Figure 11.3

Pathway of Blood through the Heart and Lungs

• Right atrium � tricuspid valve � right ventricle

• Right ventricle � pulmonary semilunar valve �pulmonary arteries � lungs

• Lungs � pulmonary veins � left atrium

• Left atrium � bicuspid valve � left ventricle

• Left ventricle � aortic semilunar valve � aorta

• Aorta � systemic circulation

Gross Anatomy of Heart: Frontal Section

Figure 19.4e

The Heart: ValvesThe Heart: Valves

Slide 11.8Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

• Allow blood to flow in only one direction

• Four valves

• Atrioventricular valves – between atria and ventricles

• Bicuspid valve (left)

• Tricuspid valve (right)

• Semilunar valves between ventricle and artery

• Pulmonary semilunar valve

• Aortic semilunar valve

Heart Valves

Figure 19.9

The Heart: ValvesThe Heart: Valves

Slide 11.9Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

• Valves open as blood is pumped through

• Held in place by chordae tendineae (“heart strings”)

• Close to prevent backflow

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Operation of Heart ValvesOperation of Heart Valves

Slide 11.10Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Figure 11.4

The Heart: Associated Great VesselsThe Heart: Associated Great Vessels

Slide 11.11Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

• Aorta

• Leaves left ventricle

• Pulmonary arteries

• Leave right ventricle

• Vena cava

• Enters right atrium

• Pulmonary veins (four)

• Enter left atrium

Coronary CirculationCoronary Circulation

Slide 11.12Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

• Blood in the heart chambers does not nourish the myocardium

• The heart has its own nourishing circulatory system

• Coronary arteries

• Cardiac veins

• Blood empties into the right atrium via the coronary sinus

The Heart: Conduction SystemThe Heart: Conduction System

Slide 11.13aCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

• Intrinsic conduction system (nodal system)

• Heart muscle cells contract, without nerve impulses, in a regular, continuous way

The Heart: Conduction SystemThe Heart: Conduction System

Slide 11.13bCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

• Special tissue sets the pace

• Sinoatrial node

• Pacemaker

• Atrioventricular node

• Atrioventricular bundle

• Bundle branches

• Purkinje fibers

Heart ContractionsHeart Contractions

Slide 11.14aCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

• Contraction is initiated by the sinoatrial node

• Sequential stimulation occurs at other autorhythmic cells

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Heart Physiology: Sequence of Excitation

• Sinoatrial (SA) node generates impulses about 75

times/minute

• Atrioventricular (AV) node delays the impulse

approximately 0.1 second

• Impulse passes from atria to ventricles via the

atrioventricular bundle (bundle of His)

Heart Physiology: Sequence of Excitation

• AV bundle splits into two pathways in the interventricular septum (bundle branches)

• Bundle branches carry the impulse toward the apex of the heart

• Purkinje fibers carry the impulse to the heart apex and ventricular walls

Heart ContractionsHeart Contractions

Slide 11.14bCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Figure 11.5

• http://www.youtube.com/watch?v=te_SY3MeWy

s

Electrocardiography

• Electrical activity is recorded by electrocardiogram (ECG)

• P wave corresponds to depolarization of atria

• QRS complex corresponds to ventricular depolarization

• T wave corresponds to ventricular repolarization

• Atrial repolarization record is masked by the larger QRS

complex

Electrocardiography

Figure 19.16

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Filling of Heart Chambers Filling of Heart Chambers ––the Cardiac Cyclethe Cardiac Cycle

Slide 11.15Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Figure 11.6

• http://www.youtube.com/watch?v=jLTdgrhpDCg

• http://www.youtube.com/watch?v=r32VObKw0g

Y

The Heart: Cardiac CycleThe Heart: Cardiac Cycle

Slide 11.16Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

• Atria contract simultaneously

• Atria relax, then ventricles contract

• Systole = contraction

• Diastole = relaxation

The Heart: Cardiac CycleThe Heart: Cardiac Cycle

Slide 11.17Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

• Cardiac cycle – events of one complete heart beat

• Mid-to-late diastole – blood flows into ventricles

• Ventricular systole – blood pressure builds before ventricle contracts, pushing out blood

• Early diastole – atria finish re-filling, ventricular pressure is low

The Heart: Cardiac OutputThe Heart: Cardiac Output

Slide 11.18Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

• Cardiac output (CO)

• Amount of blood pumped by each side of the heart in one minute

• CO = (heart rate [HR]) x (stroke volume [SV])

• Stroke volume

• Volume of blood pumped by each ventricle in one contraction

Cardiac Output RegulationCardiac Output Regulation

Slide 11.19Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Figure 11.7