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PowerPoint® Lecture Slides
prepared by Leslie Hendon,
University of Alabama,
Birmingham
18
HUMAN
ANATOMY
PART 1
The Heart
fifth edition
MARIEB | MALLATT | WILHELM
Copyright © 2008 Pearson Education, Inc.,
publishing as Benjamin Cummings
The Heart

A muscular double pump
 Pulmonary circuit – takes blood to and from the
lungs
 Systemic circuit – vessels transport blood to and
from body tissues
 Atria – receive blood from the pulmonary and
systemic circuits
 Ventricles – the pumping chambers of the heart
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
The Pulmonary and Systemic Circuits
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 18.1
Location and Orientation within the Thorax


Heart – typically weighs 250–350 grams (healthy
heart)
Largest organ of the mediastinum
 Located between the lungs
 Apex lies to the left of the midline
 Base is the broad posterior surface
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Location and Orientation within the Thorax
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 18.2
Four “Corners” of the Heart

Superior right
 At costal cartilage of third rib and sternum

Inferior right
 At costal cartilage of sixth rib lateral to the sternum

Superior left
 At costal cartilage of second rib lateral to the
sternum

Inferior left
 Lies in the fifth intercostal space at the
midclavicular line
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Location and Orientation within the Thorax
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 18.2
Structure of the Heart – Coverings

Pericardium – two primary layers
 Fibrous pericardium
 Strong layer of dense connective tissue
 Serous pericardium
 Formed from two layers
 Parietal pericardium
 Visceral pericardium
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Structure of the Heart – Coverings
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 18.3
Structure of the Heart – Layers of the Heart Wall

Epicardium
 Visceral layer of the serous pericardium

Myocardium
 Consists of cardiac muscle
 Muscle arranged in circular and spiral patterns

Endocardium
 Endothelium resting on a layer of connective tissue
 Lines the internal walls of the heart
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Structure of the Heart – Layers of the Heart Wall
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 18.4
Heart Chambers




PLAY
Right and left atria

Superior chambers
Right and left ventricles

Inferior chambers
Internal divisions


Interventricular septa
Interatrial septa
External markings



Coronary sulcus
Anterior interventricular sulcus
posterior interventricular sulcus
Rotatable Heart
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Heart Chambers
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 18.5b
Right Atrium



Forms right border of heart
Receives blood from systemic circuit
Pectinate muscles
 Ridges inside anterior of right atrium

Crista terminalis
 Landmark used to locate veins entering right
atrium

Fossa ovalis
 Depression in interatrial septum
 Remnant of foramen ovale
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Right Ventricle


Receives blood from right atrium through the
tricuspid valve
Pumps blood into pulmonary circuit via
 Pulmonary trunk

Internal walls of right ventricle
 Trabeculae carneae
 Papillary muscles
 Chordae tendineae
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Left Atrium



Makes up heart’s posterior surface
Receives oxygen-rich blood from lungs
Opens into the left ventricle through
 Mitral valve (left atrioventricular valve)
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Left Ventricle


Forms apex of the heart
Internal walls of left ventricle
 Trabeculae carneae
 Papillary muscles
 Chordae tendineae

Pumps blood through systemic circuit via
 Aortic semilunar valve (aortic valve)
PLAY
Rotatable Heart Section
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Heart Chambers
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 18.5e
Inferior View of the Heart
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 18.5d
Pathway of Blood Through the Heart

Beginning with oxygen-poor blood in the
superior and inferior venae cavae
 Go through pulmonary and systemic circuits
 A blood drop passes through all structures
sequentially
 Atria contract together
 Ventricles contract together
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Blood Flow Through the Heart
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 18.6
Pathway of Blood Through the Heart
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 18.6b
Heartbeat

70 – 80 beats per minute at rest
 Systole – contraction of a heart chamber
 Diastole – expansion of a heart chamber

Systole and diastole also refer to
 Stage of heartbeat when ventricles contract and
expand
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Structure of Heart Wall

Walls differ in thickness
 Atria – thin walls
 Ventricles – thick walls
 Systemic circuit
 Longer than pulmonary circuit
 Offers greater resistance to blood flow
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Structure of Heart Wall

Left ventricle – three
times thicker than
right
 Exerts more
pumping force
 Flattens right
ventricle into a
crescent shape
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings
Figure 18.7