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Principles of Anatomy and Physiology
Thirteenth Edition
Chapter 20The Cardiovascular System: The Heart
Copyright © 2012 by John Wiley & Sons, Inc.
Gerard J. Tortora • Bryan H. Derrickson
(a) Inferior view of transverse section of thoracic cavity showing heart in mediastinum
Sternum
Muscle
Left lung
Esophagus
Sixth thoracic vertebra
LEFT PLEURAL CAVITY
Heart
PERICARDIAL CAVITY
Right lung
Aorta
RIGHT PLEURAL CAVITY
POSTERIOR
ANTERIOR
VIEW
Transverse plane
Arch of aorta
(b) Anterior view of heart in thoracic cavity
Pulmonary trunk
Left lung
LEFT BORDER
APEX OF HEART
Superior vena cava
SUPERIOR BORDER
RIGHT BORDER
Right lung
Pleura (cut toreveal lung inside)
Diaphragm
INFERIOR SURFACE
Pericardium (cut)
Heart
Arch of aorta
(c) Anterior view
Pulmonary trunk
Left lung
Apex of heart
Diaphragm
Heart
Rib (cut)
Right lung
Superior vena cava
Pericardium
Epicardium
Myocardium
Endocardium
ENDOCARDIUM
(a) Portion of pericardium and right ventricular heart wall showing divisions of pericardium and layers of heart wall
FIBROUS PERICARDIUM
PARIETAL LAYER OFSEROUS PERICARDIUM
Coronary blood vessels
Trabeculae carneae
Pericardial cavity
MYOCARDIUM(CARDIAC MUSCLE)
VISCERAL LAYER OF SEROUS PERICARDIUM (EPICARDIUM)
PERICARDIUM
Heart wall
(c) Simplified relationship of serous pericardium to heart
Heart
Pericardialcavity Visceral layer
of serouspericardium
Parietal layerof serouspericardium
Pericardialcavity
Serous pericardium
(d) Cardiac muscle bundles of myocardium
Aorta
Pulmonary trunk
Superficial muscle bundles in atria
Superficial muscle bundles in ventricles
Superior vena cava
Deep muscle bundle in ventricle
(a) Anterior external view showing surface features
Brachiocephalic trunk
Superior vena cava
Ascending aorta
Right pulmonary artery
Fibrous pericardium (cut)
Right pulmonary veins
AURICLE OF RIGHT ATRIUM
Right coronary artery
RIGHT ATRIUM
CORONARY SULCUS (deep to fat)
RIGHT VENTRICLE
Inferior vena cava
Left common carotid artery
Left subclavian artery
Arch of aorta
Ligamentum arteriosum
Left pulmonary artery
Pulmonary trunk
Left pulmonary veins
AURICLE OF LEFT ATRIUM
Branch of left coronary artery
LEFT VENTRICLE
ANTERIOR INTERVENTRICULARSULCUS (deep to fat)
Descending aorta
(b) Anterior external view
Brachiocephalic trunk
Superior vena cava
Ascending aorta
Right pulmonary veins
RIGHT AURICLE OFRIGHT ATRIUM
RIGHT ATRIUM
CORONARY SULCUS
RIGHT VENTRICLE
Left common carotid artery
Left subclavian artery
Arch of aorta
Ligamentum arteriosum
Left pulmonary artery
Left pulmonary veins
LEFT AURICLE OF LEFT ATRIUM
LEFT VENTRICLE
ANTERIOR INTERVENTRICULARSULCUS
Pulmonary trunk
(c) Posterior external view showing surface features
Left common carotid artery
Left subclavian artery
Arch of aorta
Left pulmonary artery
Left pulmonary veins
LEFT VENTRICLE
Brachiocephalic trunk
Superior vena cava
Ascending aorta
Right pulmonary veins
RIGHT ATRIUM
RIGHT VENTRICLE
LEFT ATRIUM
Coronary sinus(in coronary sulcus)
POSTERIOR INTERVENTRICULAR SULCUS (deep to fat)
Right pulmonary artery
Right coronary artery
Inferior vena cava
Middle cardiac vein
Descending aorta
(a) Anterior view of frontal section showing internal anatomy
Frontalplane
Ascending aorta
Superior vena cava
Right pulmonary artery
PULMONARY VALVE
Right pulmonary veins
Opening of superior vena cava
Fossa ovalis
RIGHT ATRIUM
Opening of coronary sinus
Opening of inferior vena cava
TRICUSPID VALVE
RIGHT VENTRICLE
Inferior vena cava
Left common carotid artery
Left subclavian artery
Brachiocephalic trunk
Arch of aorta
Ligamentum arteriosumLeft pulmonary artery
Pulmonary trunk
Left pulmonary veins
LEFT ATRIUMAORTIC VALVE
BICUSPID (MITRAL) VALVE
CHORDAE TENDINEAE
LEFT VENTRICLE
INTERVENTRICULAR SEPTUM
PAPILLARY MUSCLE
TRABECULAE CARNEAE
Descending aorta
(b) Anterior view of partially sectioned heart
Ascending aorta
Superior vena cava
Right pulmonary artery
RIGHT ATRIUM
RIGHT VENTRICLE
Left common carotid artery
Left subclavian arteryBrachiocephalic trunk
Arch of aorta
Ligamentum arteriosum
Pulmonary trunk
Left pulmonary vein
LEFT VENTRICLE
INTERVENTRICULAR SEPTUM
TRABECULAE CARNEAE
LEFT AURICLE
RIGHT AURICLE(cut open)
Pectinate muscles
Cusp of tricuspid valve
Chordae tendineae
Papillary muscle
ANTERIOR
POSTERIOR
Right ventricleLeft ventricle
Interventricularseptum
Lumen Lumen
Transverseplane
View
(c) Inferior view of transverse section showing differences in thickness of ventricular walls
Superior view (the atria have been removed)
Transverseplane
View
PULMONARY FIBROUS RING
CONUS TENDON
AORTIC FIBROUS RING
Right coronary artery
Tricuspid valve
RIGHT ATRIOVENTRICULARFIBROUS RING
Pulmonary valve
Left coronary artery
Aortic valve
LEFT FIBROUS TRIGONE
RIGHT FIBROUS TRIGONE
Bicuspid valve
LEFT ATRIOVENTRICULARFIBROUS RING
(a) Bicuspid valve open
Leftatrium
(b) Bicuspid valve closed
Leftventricle
Open
Slack
Relaxed
Closed
Taut
Contracted
CHORDAE TENDINEAE
PAPILLARY MUSCLES
BICUSPID VALVE CUSPS
(c) Tricuspid valve open
Cusp oftricuspidvalve
Chordaetendineae
Papillarymuscle
(d) Superior view with atria removed: pulmonary and aortic valves closed, bicuspid and tricuspid valves open
Pulmonary valve (closed)
Left coronary artery
Bicuspid valve (open)
Tricuspid valve (open)
Aortic valve (closed)
Right coronary artery
POSTERIOR
ANTERIOR
(e) Superior view with atria removed: pulmonary and aortic valves open, bicuspid and tricuspid valves closed
Pulmonary valve (open)
POSTERIOR
ANTERIOR
Aortic valve (open)
Tricuspid valve (closed)
Bicuspid valve (closed)
(f) Superior view of atrioventricular and semilunar valves
POSTERIOR
ANTERIOR
Pulmonary trunk
PULMONARY VALVE
Pectinate muscle of left atrium
Left coronary artery
BICUSPID (MITRAL) VALVE
Ascending aorta
Right coronary artery
Pectinate muscle of right atrium
AORTIC VALVE
TRICUSPID VALVE
Coronary sinus
Semilunar cusp of aortic valve
(g) Superior view of aortic valve
Oxygen-rich blood
(a) Path of blood flow through heart
Oxygen-poor blood
10. 8.
5.
7.
2.
1.
3.
5.
6.
10.
4. Pulmonary capillaries of right lung
Key:
4. Pulmonary capillaries of left lung
9. Systemic capillaries of head and upper limbs
9. Systemic capillaries of trunk and lower limbs
4. In pulmonary capillaries, blood loses CO2 and gains O2
(b) Diagram of blood flow
3. Pulmonary trunk and pulmonary arteries
Pulmonary veins (oxygenated blood)
Right ventricle Left atrium
Right atrium (deoxygenated blood)
Left ventricle
Superior vena cava
Inferior vena cava
Coronarysinus
Aorta and systemic arteries
9. In systemic capillaries, blood loses O2 and gains CO2
Pulmonary valve
Tricuspid valve Bicuspid valve
Aortic valve
2.
1.
10. 8.
5.
6.
7.
(a) Anterior view of coronary arteries
Arch of aorta
LEFT CORONARY
Left auricle
CIRCUMFLEX BRANCH
ANTERIOR INTERVENTRICULAR BRANCH
POSTERIOR INTERVENTRICULAR BRANCH
Left ventricle
Ascending aorta
Pulmonary trunk
RIGHT CORONARY
Right atrium
MARGINAL BRANCH
Right ventricle
(b) Anterior view of coronary veins
Superior vena cava
Right atrium
SMALL CARDIAC
ANTERIOR CARDIAC
MIDDLE CARDIAC
Right ventricle
Inferior vena cava
Pulmonary trunk
Left auricle
CORONARY SINUS
GREAT CARDIAC
Leftventricle
(c) Anterior view
Arch of aorta
INFERIOR
SUPERIOR
Left pulmonary artery
Pulmonary trunk
Left auricle
GREAT CARDIAC VEIN
LEFT CORONARY ARTERY
CIRCUMFLEX BRANCH
LEFT MARGINAL BRANCH
Left ventricle
TRIBUTARY TO GREAT CARDIAC VEIN
Ascending aorta
Right auricle
RIGHT CORONARY ARTERY
ANTERIOR CARDIAC VEIN
Right ventricle
MARGINAL BRANCH
ANTERIOR INTERVENTRICULAR BRANCH
(a) Cardiac muscle fibers
Desmosomes
Mitochondrion
Intercalateddiscs
Opening oftransversetubule
Gap junctions
Cardiac muscle fiber (cell)
NucleusSarcolemma
(b) Arrangement of components in a cardiac muscle fiber
Nucleus
Sarcolemma Transversetubule
Mitochondrion Sarcoplasmicreticulum
Thin filament
Thick filament
Z disc M line
H zone
Z disc
I band A band I band
Sarcomere
(a) Anterior view of frontal section
Frontal plane
Right atrium
SINOATRIAL (SA) NODE
ATRIOVENTRICULAR (AV) NODE
ATRIOVENTRICULAR (AV) BUNDLE (BUNDLE OF HIS)
RIGHT AND LEFT BUNDLE BRANCHES
PURKINJE FIBERS
Right ventricle
Left atrium
Left ventricle
1
2
3
4
5
(b) Pacemaker potentials and action potentials in autorhythmic fibers of SA node
+ 10 mV
– 60 mV
Membranepotential
Actionpotential
Threshold
Pacemakerpotential
0 0.8 1.6 2.4
Time (sec)
Contraction
MembranePotential (mV)
Refractory period
Depolarization Repolarization
Rapid depolarization due to Na+ inflow when voltage-gated fast Na+ channels open
Plateau (maintained depolarization) due to Ca2+ inflow when voltage-gated slow Ca2+ channels open and K+ outflow when some K+ channels open
Repolarization due to closure of Ca2+ channels and K+ outflow when additional voltage-gated K+ channels open1
2
3
0.3 sec
Atrial contraction
Seconds
Mil
livo
lts
(mV
)
Ventricular contraction
Key:
P
R
Q
S
T
S–Tsegment
P–Qinterval
Q–T interval
Ventricular diastole(relaxation)
6Repolarization of ventricular contractile fibers produces T wave
5Ventricular systole(contraction)
4
Depolarization of ventricular contractile fibers produces QRS complex
3Atrial systole(contraction)
2Depolarization of atrial contractile fibers produces P wave
1
Action potentialin SA node
P P P
P P P
R
QS
T
(a) ECG
(b) Pressure(mmHg)
(c) Heart sounds
120
P
QS
T
R
0.1 sec 0.3 sec 0.4 secAtrialsystole
Ventricularsystole
Relaxationperiod
100
80
60
40
20
0
Aortic valvecloses
Bicuspidvalvecloses
Aortic valveopens
Bicuspidvalve opens
Aorticpressure
Leftventricularpressure
Left atrialpressure
S1 S2 S3 S4
1
4
8
9
6
5
2
10
Dicrotic wave
Atrialcontraction
Isovolumetriccontraction
Ventricularejection
Isovolumetricrelaxation
Ventricularfilling
Atrialcontraction
130
60
0
(d) Volume inventricle (mL)
(e) Phases of thecardiac cycle
3
7
(c) Heart sounds
S1 S2 S3 S4
End-systolic volume
End-diastolic volumeEnd-diastolic volume
Strokevolume
Aortic valve
Tricuspid valve
Pulmonary valve
Bicuspid valve
1
2
3
4
5
6
Anterior view of heart valve locations and auscultation sites
INPUT TO CARDIOVASCULAR CENTER
From higher brain centers: cerebralcortex, limbic system, and hypothalamus
From sensory receptors:Proprioceptors—monitor movementsChemoreceptors—monitor blood chemistryBaroreceptors—monitor blood pressure
OUTPUT TO HEART
Increased rate of spontaneous depolarization in SA node (and AV node) increases heart rate
Increased contractility of atria and ventricles increases stroke volume
Decreased rate of spontaneous depolarization in SA node (and AV node) decreases heart rate
Cardiac accelerator
nerves (sympathetic)
Vagus nerves (cranial
nerve X, parasympathetic
Cardiovascular(CV) center
Increased end-diastolic volume (stretches the heart)
Positive inotropic agents such as increased sympathetic stimulation; catecholamines, glucagon, or thyroid hormones in the blood; increased Ca2+ in extracellular fluid
Decreased arterial blood pressure during diastole
Increased PRELOAD Increased CONTRACTILITY Decreased AFTERLOAD
Within limits, cardiac muscle fibers contract more forcefully with stretching (Frank–Starling law of the heart)
Positive inotropic agents increase force of contraction at all physiological levels of stretch
Semilunar valves open sooner when blood pressure in aorta and pulmonary artery is lower
Increased STROKE VOLUME
Increased HEART RATE
CHEMICALS
Increased CARDIAC OUTPUT
OTHER FACTORSNERVOUS SYSTEMCardiovascular center in medulla oblongata receives input from cerebral cortex, limbic system, proprioceptors, baroreceptors, and chemoreceptors
Increased sympathetic stimulation and decreased parasympathetic stimulation
Catecholamine or thyroid hormones in the blood; moderate increase in extracellular Ca2+
Infants and senior citizens, females, low physical fitness, increased body temperature
(a) Donor’s left atrium is sutured to recipient's left atrium
Aorta
Pulmonary artery
Superior vena cava
Partial left atrium
Inferior vena cava
Left atrium
Right atrium
Recipient's heart
Donor's heart
(b) Donor's right atrium is sutured to recipient's superior and inferior venae cavae
Recipient's superior vena cava
Donor's right atrium
Recipient's inferior vena cava
(c) Transplanted heart with sutures
Thoracicaorta
Catheter
Anterior view
Posterior view
(a) Intra-aortic balloon pump
Outflowtube
Outflowone-way valve
Driveline
Parts of left ventricularassist device (LVAD)
Pump unit
Inflow one-way valve
Implanted left ventricular assist device (LVAD)
Aorta
Leftventricle
Inflowtube
(b) Left ventricular assist device (LVAD)
(a) Location of cardiogenic area
Cardiogenicarea
(b) Formation of endocardial tubes
(c) Formation of primitive heart tube
(d) Development of regions in the primitive heart tube
(e) Bending of the primitive heart (f) Orientation of atria and ventricles to their final adult position
19 days 20 days 21 days 22 daysVenous end of heart
23 days 24 days 28 days
Neural plate
Head end Arterial end of heart
Endocardialtubes
Fusion of endocardial tubes into primitive heart tube
Truncus arteriosus
Bulbus cordis
Primitive ventricle
Primitive atrium
Sinus venosus
Aorta
Pulmonary trunk
Atrium
Ventricle
Superior vena cava
Inferior vena cava
Truncus arteriosus
Bulbus cordis
Primitive ventricle
Primitive atrium
Sinus venosus
Superior vena cava
About 28 days
Future interatrial septum
Ventricle
Future interventricular septum
Pulmonary veins
Atrium
Endocardial cushion
Inferior vena cava
Atrioventricular canals
Right atrium
About 8 weeks
Tricuspid valve
Right ventricle
Foramen ovale
Left atrium
Left ventricle
Bicuspid valve
Partially obstructed space through which blood flows
(a) Normal artery (b) Obstructed artery
Atherosclerotic plaque
LM 20xLM 16x
(a) Coronary artery bypass grafting (CABG)
Ascendingaorta
Graftedvessel
Obstruction
(b) Percutaneous transluminal coronary angioplasty (PTCA)
Balloon
Balloon catheter with uninflated balloon is threaded to obstructed area in artery
When balloon is inflated, it stretches arterial wall and squashes atherosclerotic plaque
After lumen is widened, balloon is deflated and catheter is withdrawn
Atheroscleroticplaque
Narrowed lumenof artery
Coronaryartery
(d) Angiogram showing a stent in the circumflex artery
Stent
(c) Stent in an artery
Lumenof artery
Narrow segment of aorta
(a) Coarctation of the aorta (b) Patent ductus arteriosus (c) Atrial septal defect
(d) Ventricular septal defect (e) Tetralogy of Fallot
Ductus arteriosusremains open
Foramen ovale fails to close
Opening ininterventricularseptum
Stenosedpulmonaryvalve
Interventricularseptal defect
Enlarged (hypertrophied) right ventricle
Aorta emergesfrom both ventricles
(a) Normal electrocardiogram (ECG)
R–R interval
P–Rinterval
(b) First-degree AV block
Long P–Rinterval
(c) Atrial fibrillation
Irregular R–R intervals
No detectable P waves
(d) Ventricular tachycardia
Ventricular fibrillation
(e) Ventricular fibrillation
Ventricular tachycardia
